diff --git a/headers/modsecurity/actions/action.h b/headers/modsecurity/actions/action.h
index f42991df..72a95069 100644
--- a/headers/modsecurity/actions/action.h
+++ b/headers/modsecurity/actions/action.h
@@ -39,35 +39,27 @@ namespace actions {
 
 class Action {
  public:
-
     explicit Action(const std::string& _action)
-        : m_isNone(false),
-        temporaryAction(false),
-        action_kind(2),
+        : m_actionKind(2),
         m_name(nullptr),
         m_parser_payload("") {
             set_name_and_payload(_action);
         }
+
     Action(const std::string& _action, int kind)
-        : m_isNone(false),
-        temporaryAction(false),
-        action_kind(kind),
+        : m_actionKind(kind),
         m_name(nullptr),
         m_parser_payload("") {
             set_name_and_payload(_action);
         }
 
     Action(const Action &a)
-        : m_isNone(a.m_isNone),
-        temporaryAction(a.temporaryAction),
-        action_kind(a.action_kind),
+        : m_actionKind(a.m_actionKind),
         m_name(a.m_name),
         m_parser_payload(a.m_parser_payload) { }
 
     Action &operator=(const Action& a) {
-        m_isNone = a.m_isNone;
-        temporaryAction = a.temporaryAction;
-        action_kind = a.action_kind;
+        m_actionKind = a.m_actionKind;
         m_name = a.m_name;
         m_parser_payload = a.m_parser_payload;
         return *this;
@@ -75,52 +67,24 @@ class Action {
 
     virtual ~Action() { }
 
+    virtual bool init(std::string *error) { return true; }
+
     virtual std::string execute(const std::string &exp,
         Transaction *transaction);
-    virtual bool execute(RuleWithActions *rule, Transaction *transaction);
-
+    virtual bool execute(RuleWithActions *rule,
+        Transaction *transaction);
     /**
      * This method is meant to be used by transformations — a particular
      * type of action.
      *
      */
     virtual void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) {
+        ModSecString &in,
+        ModSecString &out) {
     };
 
-    virtual bool init(std::string *error) { return true; }
     virtual bool isDisruptive() { return false; }
 
-
-    void set_name_and_payload(const std::string& data) {
-        size_t pos = data.find(":");
-        std::string t = "t:";
-
-        if (data.compare(0, t.length(), t) == 0) {
-            pos = data.find(":", 2);
-        }
-
-        if (pos == std::string::npos) {
-            m_name = std::shared_ptr<std::string>(new std::string(data));
-            return;
-        }
-
-        m_name = std::shared_ptr<std::string>(new std::string(data, 0, pos));
-        m_parser_payload = std::string(data, pos + 1, data.length());
-
-        if (m_parser_payload.at(0) == '\'' && m_parser_payload.size() > 2) {
-            m_parser_payload.erase(0, 1);
-            m_parser_payload.pop_back();
-        }
-    }
-
-    bool m_isNone;
-    bool temporaryAction;
-    int action_kind;
-    std::shared_ptr<std::string> m_name;
-    std::string m_parser_payload;
-
     /**
      *
      * Define the action kind regarding to the execution time.
@@ -152,7 +116,35 @@ class Action {
      */
      RunTimeOnlyIfMatchKind,
     };
- };
+
+    int m_actionKind;
+    std::shared_ptr<std::string> m_name;
+    std::string m_parser_payload;
+
+ private:
+
+    void set_name_and_payload(const std::string& data) {
+        size_t pos = data.find(":");
+        std::string t = "t:";
+
+        if (data.compare(0, t.length(), t) == 0) {
+            pos = data.find(":", 2);
+        }
+
+        if (pos == std::string::npos) {
+            m_name = std::shared_ptr<std::string>(new std::string(data));
+            return;
+        }
+
+        m_name = std::shared_ptr<std::string>(new std::string(data, 0, pos));
+        m_parser_payload = std::string(data, pos + 1, data.length());
+
+        if (m_parser_payload.at(0) == '\'' && m_parser_payload.size() > 2) {
+            m_parser_payload.erase(0, 1);
+            m_parser_payload.pop_back();
+        }
+    }
+};
 
 
 }  // namespace actions
diff --git a/headers/modsecurity/modsecurity.h b/headers/modsecurity/modsecurity.h
index 7eac444c..51e64f53 100644
--- a/headers/modsecurity/modsecurity.h
+++ b/headers/modsecurity/modsecurity.h
@@ -89,6 +89,12 @@
 typedef struct ModSecurity_t modsecurity;
 #else
 namespace modsecurity {
+    /**
+     *  Further that will be changed to be a stack-based string,
+     * for the benefit of performance.
+     */
+    using ModSecString = std::string;
+
     /**
      *
      * The Phases enumerator consists in mapping the different stages of a
diff --git a/headers/modsecurity/rule_with_actions.h b/headers/modsecurity/rule_with_actions.h
index d71ffeea..085a65dd 100644
--- a/headers/modsecurity/rule_with_actions.h
+++ b/headers/modsecurity/rule_with_actions.h
@@ -64,18 +64,17 @@ using MatchActionsPtr = std::vector<actions::Action *>;
 using XmlNSs = std::vector<std::shared_ptr<actions::XmlNS> >;
 using XmlNSsPtr = std::vector<actions::XmlNS *>;
 
-using ModSecStackString = std::basic_string<char, std::char_traits<char>, std::allocator<char> >;
 
 class TransformationResult {
  public:
     TransformationResult(
-        ModSecStackString *after,
+        ModSecString *after,
         std::string *transformation)
         : m_after(*after),
         m_transformation(transformation) { };
 
     explicit TransformationResult(
-        ModSecStackString *after)
+        ModSecString *after)
         : m_after(*after),
         m_transformation(nullptr) { };
 
@@ -84,7 +83,7 @@ class TransformationResult {
         m_transformation(t2.m_transformation) { };
 
 
-    ModSecStackString *getAfter() {
+    ModSecString *getAfter() {
         return &m_after;
     }
 
@@ -95,7 +94,7 @@ class TransformationResult {
 
 
  private:
-    ModSecStackString m_after;
+    ModSecString m_after;
     std::string *m_transformation;
 };
 
@@ -224,7 +223,7 @@ class RuleWithActions : public Rule {
 
     static void executeTransformation(
         Transaction *transaction,
-        ModSecStackString in,
+        ModSecString in,
         TransformationsResults *ret,
         Transformation *transformation);
 
diff --git a/headers/modsecurity/rules.h b/headers/modsecurity/rules.h
index 1ed88ebc..43198b7c 100644
--- a/headers/modsecurity/rules.h
+++ b/headers/modsecurity/rules.h
@@ -40,52 +40,20 @@ namespace modsecurity {
 
 class Rules {
  public:
-    void dump() const {
-        for (int j = 0; j < m_rules.size(); j++) {
-            std::cout << "    Rule ID: " << m_rules.at(j)->getReference();
-            std::cout << "--" << m_rules.at(j) << std::endl;
-        }
-    }
+    void dump() const;
 
-    int append(Rules *from, const std::vector<int64_t> &ids, std::ostringstream *err) {
-         size_t j = 0;
-         for (; j < from->size(); j++) {
-            RuleWithOperator *rule = dynamic_cast<RuleWithOperator *>(from->at(j).get());
-            if (rule && std::binary_search(ids.begin(), ids.end(), rule->getId())) {
-                 if (err != NULL) {
-                     *err << "Rule id: " << std::to_string(rule->getId()) \
-                        << " is duplicated" << std::endl;
-                 }
-                 return -1;
-             }
-         }
-         m_rules.insert(m_rules.end(), from->m_rules.begin(), from->m_rules.end());
-         return j;
-    }
+    int append(Rules *from, const std::vector<int64_t> &ids, std::ostringstream *err);
 
-    bool insert(const std::shared_ptr<Rule> &rule) {
-        return insert(rule, nullptr, nullptr);
-    }
+    bool insert(const std::shared_ptr<Rule> &rule);
 
-    bool insert(std::shared_ptr<Rule> rule, const std::vector<int64_t> *ids, std::ostringstream *err) {
-        RuleWithOperator *r = dynamic_cast<RuleWithOperator *>(rule.get());
-        if (r && ids != nullptr && std::binary_search(ids->begin(), ids->end(), r->getId())) {
-            if (err != nullptr) {
-                *err << "Rule id: " << std::to_string(r->getId()) \
-                    << " is duplicated" << std::endl;
-            }
-            return false;
-        }
-        m_rules.push_back(rule);
-        return true;
-    }
+    bool insert(std::shared_ptr<Rule> rule, const std::vector<int64_t> *ids, std::ostringstream *err);
+
+    size_t size() const;
+    std::shared_ptr<Rule> operator[](int index) const;
+    std::shared_ptr<Rule> at(int index) const;
 
     void fixDefaultActions();
 
-    size_t size() const { return m_rules.size(); }
-    std::shared_ptr<Rule> operator[](int index) const { return m_rules[index]; }
-    std::shared_ptr<Rule> at(int index) const { return m_rules[index]; }
-
     std::vector<std::shared_ptr<actions::Action> > m_defaultActions;
     std::vector<std::shared_ptr<actions::transformations::Transformation> > m_defaultTransformations;
 
diff --git a/headers/modsecurity/transaction.h b/headers/modsecurity/transaction.h
index a99e9bd0..0752780c 100644
--- a/headers/modsecurity/transaction.h
+++ b/headers/modsecurity/transaction.h
@@ -49,7 +49,6 @@ typedef struct Rules_t RulesSet;
 #include "modsecurity/collection/collection.h"
 #include "modsecurity/variable_origin.h"
 
-
 #ifndef NO_LOGS
 #define ms_dbg(b, c) \
   do { \
diff --git a/src/Makefile.am b/src/Makefile.am
index e6496ccc..b90e2ffb 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -42,10 +42,6 @@ pkginclude_HEADERS = \
 	../headers/modsecurity/intervention.h \
 	../headers/modsecurity/modsecurity.h \
 	../headers/modsecurity/rule.h \
-	../headers/modsecurity/rule_marker.h \
-	../headers/modsecurity/rule_unconditional.h \
-	../headers/modsecurity/rule_with_actions.h \
-	../headers/modsecurity/rule_with_operator.h \
 	../headers/modsecurity/rules.h \
 	../headers/modsecurity/rule_message.h \
 	../headers/modsecurity/rules_set.h \
@@ -286,6 +282,7 @@ libmodsecurity_la_SOURCES = \
 	debug_log/debug_log_writer.cc \
 	run_time_string.cc \
 	rule.cc \
+	rules.cc \
 	rule_unconditional.cc \
 	rule_with_actions.cc \
 	rule_with_operator.cc \
diff --git a/src/actions/accuracy.cc b/src/actions/accuracy.cc
index 7fcd44bc..66cb913d 100644
--- a/src/actions/accuracy.cc
+++ b/src/actions/accuracy.cc
@@ -21,7 +21,7 @@
 #include "modsecurity/actions/action.h"
 #include "modsecurity/transaction.h"
 #include "modsecurity/rule.h"
-
+#include "modsecurity/rule_with_actions.h"
 
 namespace modsecurity {
 namespace actions {
diff --git a/src/actions/block.cc b/src/actions/block.cc
index 757c1d12..c20cf6ab 100644
--- a/src/actions/block.cc
+++ b/src/actions/block.cc
@@ -24,6 +24,7 @@
 #include "modsecurity/rule.h"
 #include "modsecurity/intervention.h"
 #include "src/actions/data/status.h"
+#include "modsecurity/rule_with_actions.h"
 
 namespace modsecurity {
 namespace actions {
diff --git a/src/actions/chain.cc b/src/actions/chain.cc
index bcd27a74..b2ac0990 100644
--- a/src/actions/chain.cc
+++ b/src/actions/chain.cc
@@ -20,6 +20,8 @@
 
 #include "modsecurity/transaction.h"
 #include "modsecurity/rule.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace actions {
diff --git a/src/actions/maturity.cc b/src/actions/maturity.cc
index 33b78855..1d6ae4a0 100644
--- a/src/actions/maturity.cc
+++ b/src/actions/maturity.cc
@@ -21,7 +21,7 @@
 #include "modsecurity/actions/action.h"
 #include "modsecurity/transaction.h"
 #include "modsecurity/rule.h"
-
+#include "modsecurity/rule_with_actions.h"
 
 namespace modsecurity {
 namespace actions {
diff --git a/src/actions/phase.cc b/src/actions/phase.cc
index 3099592b..4cba84c4 100644
--- a/src/actions/phase.cc
+++ b/src/actions/phase.cc
@@ -22,6 +22,7 @@
 #include "modsecurity/rule.h"
 #include "modsecurity/modsecurity.h"
 #include "src/utils/string.h"
+#include "modsecurity/rule_with_actions.h"
 
 
 namespace modsecurity {
diff --git a/src/actions/rev.cc b/src/actions/rev.cc
index 86369ebb..e2ec45e7 100644
--- a/src/actions/rev.cc
+++ b/src/actions/rev.cc
@@ -21,6 +21,7 @@
 #include "modsecurity/actions/action.h"
 #include "modsecurity/transaction.h"
 #include "modsecurity/rule.h"
+#include "modsecurity/rule_with_actions.h"
 
 
 namespace modsecurity {
diff --git a/src/actions/rule_id.cc b/src/actions/rule_id.cc
index 7d68fe60..40424933 100644
--- a/src/actions/rule_id.cc
+++ b/src/actions/rule_id.cc
@@ -20,6 +20,8 @@
 
 #include "modsecurity/transaction.h"
 #include "modsecurity/rule.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace actions {
diff --git a/src/actions/set_env.cc b/src/actions/set_env.cc
index e5d080bb..2d92d48c 100644
--- a/src/actions/set_env.cc
+++ b/src/actions/set_env.cc
@@ -21,6 +21,8 @@
 #include "modsecurity/transaction.h"
 #include "modsecurity/rule.h"
 #include "src/utils/string.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace actions {
diff --git a/src/actions/set_var.cc b/src/actions/set_var.cc
index e97297e5..2ae13606 100644
--- a/src/actions/set_var.cc
+++ b/src/actions/set_var.cc
@@ -30,6 +30,7 @@
 #include "src/variables/tx.h"
 #include "src/variables/user.h"
 #include "src/variables/variable.h"
+#include "modsecurity/rule_with_operator.h"
 
 namespace modsecurity {
 namespace actions {
diff --git a/src/actions/transformations/base64_decode.cc b/src/actions/transformations/base64_decode.cc
index 08d72f11..40a7a442 100644
--- a/src/actions/transformations/base64_decode.cc
+++ b/src/actions/transformations/base64_decode.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void Base64Decode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     std::string value(in.c_str(), in.size());
     std::string ret = Utils::Base64::decode(value);
     out.assign(ret.c_str(), ret.size());
diff --git a/src/actions/transformations/base64_decode.h b/src/actions/transformations/base64_decode.h
index 55e172a4..e96c1e15 100644
--- a/src/actions/transformations/base64_decode.h
+++ b/src/actions/transformations/base64_decode.h
@@ -34,8 +34,8 @@ class Base64Decode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/base64_decode_ext.cc b/src/actions/transformations/base64_decode_ext.cc
index 07a77ad0..f582d7e4 100644
--- a/src/actions/transformations/base64_decode_ext.cc
+++ b/src/actions/transformations/base64_decode_ext.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void Base64DecodeExt::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     std::string ret = Utils::Base64::decode_forgiven(in.c_str());
     out.assign(ret.c_str(), ret.size());
 }
diff --git a/src/actions/transformations/base64_decode_ext.h b/src/actions/transformations/base64_decode_ext.h
index ed9edf78..3f36fc9f 100644
--- a/src/actions/transformations/base64_decode_ext.h
+++ b/src/actions/transformations/base64_decode_ext.h
@@ -34,8 +34,8 @@ class Base64DecodeExt : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/base64_encode.cc b/src/actions/transformations/base64_encode.cc
index 4bc7871a..3560d6eb 100644
--- a/src/actions/transformations/base64_encode.cc
+++ b/src/actions/transformations/base64_encode.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void Base64Encode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     std::string ret = Utils::Base64::encode(
         std::string(in.c_str(), in.size()));
     out.assign(ret.c_str(), ret.size());
diff --git a/src/actions/transformations/base64_encode.h b/src/actions/transformations/base64_encode.h
index 2c816d6b..1158a5c5 100644
--- a/src/actions/transformations/base64_encode.h
+++ b/src/actions/transformations/base64_encode.h
@@ -34,8 +34,8 @@ class Base64Encode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/cmd_line.cc b/src/actions/transformations/cmd_line.cc
index acb572ac..4082bed6 100644
--- a/src/actions/transformations/cmd_line.cc
+++ b/src/actions/transformations/cmd_line.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void CmdLine::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int space = 0;
 
     for (auto& a : in) {
diff --git a/src/actions/transformations/cmd_line.h b/src/actions/transformations/cmd_line.h
index a853ad83..3724b515 100644
--- a/src/actions/transformations/cmd_line.h
+++ b/src/actions/transformations/cmd_line.h
@@ -34,8 +34,8 @@ class CmdLine : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/compress_whitespace.cc b/src/actions/transformations/compress_whitespace.cc
index a11c6ea4..7d1af976 100644
--- a/src/actions/transformations/compress_whitespace.cc
+++ b/src/actions/transformations/compress_whitespace.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void CompressWhitespace::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int inWhiteSpace = 0;
     size_t i = 0;
     out.reserve(in.size());
diff --git a/src/actions/transformations/compress_whitespace.h b/src/actions/transformations/compress_whitespace.h
index 11d7b120..de14f33a 100644
--- a/src/actions/transformations/compress_whitespace.h
+++ b/src/actions/transformations/compress_whitespace.h
@@ -34,8 +34,8 @@ class CompressWhitespace : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/css_decode.cc b/src/actions/transformations/css_decode.cc
index 05485d75..1ca7a824 100644
--- a/src/actions/transformations/css_decode.cc
+++ b/src/actions/transformations/css_decode.cc
@@ -35,17 +35,19 @@ namespace transformations {
 
 
 void CssDecode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
+    size_t s = in.size();
+
     char *tmp = reinterpret_cast<char *>(
-        malloc(sizeof(char) * in.size() + 1));
-    memcpy(tmp, in.c_str(), in.size() + 1);
-    tmp[in.size()] = '\0';
+        malloc(sizeof(char) * s + 1));
+    memcpy(tmp, in.c_str(), s + 1);
+    tmp[s] = '\0';
 
-    CssDecode::css_decode_inplace(reinterpret_cast<unsigned char *>(tmp),
-        in.size());
+    size_t r = CssDecode::css_decode_inplace(reinterpret_cast<unsigned char *>(tmp),
+        s);
 
-    out.assign(tmp, 0, in.size());
+    out.assign(tmp, r);
     free(tmp);
 }
 
diff --git a/src/actions/transformations/css_decode.h b/src/actions/transformations/css_decode.h
index 112b3391..1be00f48 100644
--- a/src/actions/transformations/css_decode.h
+++ b/src/actions/transformations/css_decode.h
@@ -35,8 +35,8 @@ class CssDecode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int css_decode_inplace(unsigned char *input, int64_t input_len);
 };
diff --git a/src/actions/transformations/escape_seq_decode.cc b/src/actions/transformations/escape_seq_decode.cc
index b81f5d72..073d314f 100644
--- a/src/actions/transformations/escape_seq_decode.cc
+++ b/src/actions/transformations/escape_seq_decode.cc
@@ -136,8 +136,8 @@ int EscapeSeqDecode::ansi_c_sequences_decode_inplace(unsigned char *input,
 
 
 void EscapeSeqDecode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *tmp = (unsigned char *) malloc(sizeof(char)
         * in.size() + 1);
     memcpy(tmp, in.c_str(), in.size() + 1);
diff --git a/src/actions/transformations/escape_seq_decode.h b/src/actions/transformations/escape_seq_decode.h
index f8c27fe1..7b690687 100644
--- a/src/actions/transformations/escape_seq_decode.h
+++ b/src/actions/transformations/escape_seq_decode.h
@@ -34,8 +34,8 @@ class EscapeSeqDecode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int ansi_c_sequences_decode_inplace(unsigned char *input, int input_len);
 };
diff --git a/src/actions/transformations/hex_decode.cc b/src/actions/transformations/hex_decode.cc
index 13538a0e..212bcbee 100644
--- a/src/actions/transformations/hex_decode.cc
+++ b/src/actions/transformations/hex_decode.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void HexDecode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
     int size = 0;
 
diff --git a/src/actions/transformations/hex_decode.h b/src/actions/transformations/hex_decode.h
index 3501f138..58645cea 100644
--- a/src/actions/transformations/hex_decode.h
+++ b/src/actions/transformations/hex_decode.h
@@ -34,8 +34,8 @@ class HexDecode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int inplace(unsigned char *data, int len);
 };
diff --git a/src/actions/transformations/hex_encode.cc b/src/actions/transformations/hex_encode.cc
index 751970c5..4a70e896 100644
--- a/src/actions/transformations/hex_encode.cc
+++ b/src/actions/transformations/hex_encode.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void HexEncode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     std::stringstream result;
     for (std::size_t i=0; i < in.length(); i++) {
         int ii = reinterpret_cast<char>(in[i]);
diff --git a/src/actions/transformations/hex_encode.h b/src/actions/transformations/hex_encode.h
index 2f8414e5..1e6ae842 100644
--- a/src/actions/transformations/hex_encode.h
+++ b/src/actions/transformations/hex_encode.h
@@ -34,8 +34,8 @@ class HexEncode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
 };
 
diff --git a/src/actions/transformations/html_entity_decode.cc b/src/actions/transformations/html_entity_decode.cc
index 080f0c75..c2909e09 100644
--- a/src/actions/transformations/html_entity_decode.cc
+++ b/src/actions/transformations/html_entity_decode.cc
@@ -34,8 +34,8 @@ namespace transformations {
 
 
 void HtmlEntityDecode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
 
     input = reinterpret_cast<unsigned char *>
diff --git a/src/actions/transformations/html_entity_decode.h b/src/actions/transformations/html_entity_decode.h
index b2b39a7d..f315fb91 100644
--- a/src/actions/transformations/html_entity_decode.h
+++ b/src/actions/transformations/html_entity_decode.h
@@ -37,8 +37,8 @@ class HtmlEntityDecode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int inplace(unsigned char *input, uint64_t input_len);
 };
diff --git a/src/actions/transformations/js_decode.cc b/src/actions/transformations/js_decode.cc
index 268e0321..32640cad 100644
--- a/src/actions/transformations/js_decode.cc
+++ b/src/actions/transformations/js_decode.cc
@@ -35,8 +35,8 @@ namespace transformations {
 
 
 void JsDecode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
 
     input = reinterpret_cast<unsigned char *>
diff --git a/src/actions/transformations/js_decode.h b/src/actions/transformations/js_decode.h
index 013e4d92..c029e611 100644
--- a/src/actions/transformations/js_decode.h
+++ b/src/actions/transformations/js_decode.h
@@ -34,8 +34,8 @@ class JsDecode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int inplace(unsigned char *input, uint64_t input_len);
 };
diff --git a/src/actions/transformations/length.cc b/src/actions/transformations/length.cc
index d620de31..57f6ae2f 100644
--- a/src/actions/transformations/length.cc
+++ b/src/actions/transformations/length.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void Length::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     out.assign(std::to_string(in.size()).c_str());
 }
 
diff --git a/src/actions/transformations/length.h b/src/actions/transformations/length.h
index bd643005..39828159 100644
--- a/src/actions/transformations/length.h
+++ b/src/actions/transformations/length.h
@@ -34,8 +34,8 @@ class Length : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/lower_case.cc b/src/actions/transformations/lower_case.cc
index fb974794..137227ef 100644
--- a/src/actions/transformations/lower_case.cc
+++ b/src/actions/transformations/lower_case.cc
@@ -28,8 +28,8 @@ namespace transformations {
 
 
 void LowerCase::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     std::locale loc;
     out.resize(in.size());
     for (std::string::size_type i=0; i < in.size(); ++i) {
diff --git a/src/actions/transformations/lower_case.h b/src/actions/transformations/lower_case.h
index 2f885914..79852094 100644
--- a/src/actions/transformations/lower_case.h
+++ b/src/actions/transformations/lower_case.h
@@ -36,8 +36,8 @@ class LowerCase : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/md5.cc b/src/actions/transformations/md5.cc
index 3996645a..a179e174 100644
--- a/src/actions/transformations/md5.cc
+++ b/src/actions/transformations/md5.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void Md5::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     std::string ret = Utils::Md5::digest(std::string(in.c_str(), in.size()));
 
     out.assign(ret.c_str(), ret.size());
diff --git a/src/actions/transformations/md5.h b/src/actions/transformations/md5.h
index c822eecf..5b86b0ca 100644
--- a/src/actions/transformations/md5.h
+++ b/src/actions/transformations/md5.h
@@ -34,8 +34,8 @@ class Md5 : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/none.cc b/src/actions/transformations/none.cc
index f093c550..00b5aadc 100644
--- a/src/actions/transformations/none.cc
+++ b/src/actions/transformations/none.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void None::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) { }
+    ModSecString &in,
+    ModSecString &out) { }
 
 
 }  // namespace transformations
diff --git a/src/actions/transformations/none.h b/src/actions/transformations/none.h
index e69c3b07..130cbb74 100644
--- a/src/actions/transformations/none.h
+++ b/src/actions/transformations/none.h
@@ -32,11 +32,15 @@ class None : public Transformation {
  public:
     explicit None(const std::string &action) 
         : Transformation(action)
-        { m_isNone = true; }
+        {  }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
+
+    bool isNone() override {
+        return true;
+    }
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/normalise_path.cc b/src/actions/transformations/normalise_path.cc
index 16290e34..c7ff95a9 100644
--- a/src/actions/transformations/normalise_path.cc
+++ b/src/actions/transformations/normalise_path.cc
@@ -34,8 +34,8 @@ namespace transformations {
 
 
 void NormalisePath::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int changed = 0;
 
     char *tmp = reinterpret_cast<char *>(
diff --git a/src/actions/transformations/normalise_path.h b/src/actions/transformations/normalise_path.h
index a5667f13..7fd91fc1 100644
--- a/src/actions/transformations/normalise_path.h
+++ b/src/actions/transformations/normalise_path.h
@@ -34,8 +34,8 @@ class NormalisePath : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int normalize_path_inplace(unsigned char *input, int input_len,
         int win, int *changed);
diff --git a/src/actions/transformations/normalise_path_win.cc b/src/actions/transformations/normalise_path_win.cc
index 7b0541f7..a3746618 100644
--- a/src/actions/transformations/normalise_path_win.cc
+++ b/src/actions/transformations/normalise_path_win.cc
@@ -35,8 +35,8 @@ namespace transformations {
 
 
 void NormalisePathWin::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int changed;
 
     char *tmp = reinterpret_cast<char *>(
diff --git a/src/actions/transformations/normalise_path_win.h b/src/actions/transformations/normalise_path_win.h
index 48be406b..3d7c8d75 100644
--- a/src/actions/transformations/normalise_path_win.h
+++ b/src/actions/transformations/normalise_path_win.h
@@ -34,8 +34,8 @@ class NormalisePathWin : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/parity_even_7bit.cc b/src/actions/transformations/parity_even_7bit.cc
index 2e8c874f..29d547da 100644
--- a/src/actions/transformations/parity_even_7bit.cc
+++ b/src/actions/transformations/parity_even_7bit.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void ParityEven7bit::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
 
     input = reinterpret_cast<unsigned char *>
diff --git a/src/actions/transformations/parity_even_7bit.h b/src/actions/transformations/parity_even_7bit.h
index ac4f7ac6..de250260 100644
--- a/src/actions/transformations/parity_even_7bit.h
+++ b/src/actions/transformations/parity_even_7bit.h
@@ -34,8 +34,8 @@ class ParityEven7bit : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static bool inplace(unsigned char *input, uint64_t input_len);
 };
diff --git a/src/actions/transformations/parity_odd_7bit.cc b/src/actions/transformations/parity_odd_7bit.cc
index ca6946fe..d2695826 100644
--- a/src/actions/transformations/parity_odd_7bit.cc
+++ b/src/actions/transformations/parity_odd_7bit.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void ParityOdd7bit::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
 
     input = reinterpret_cast<unsigned char *>
diff --git a/src/actions/transformations/parity_odd_7bit.h b/src/actions/transformations/parity_odd_7bit.h
index a99a488d..823b7fc7 100644
--- a/src/actions/transformations/parity_odd_7bit.h
+++ b/src/actions/transformations/parity_odd_7bit.h
@@ -34,8 +34,8 @@ class ParityOdd7bit : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static bool inplace(unsigned char *input, uint64_t input_len);
 };
diff --git a/src/actions/transformations/parity_zero_7bit.cc b/src/actions/transformations/parity_zero_7bit.cc
index d54e8e13..25e24f42 100644
--- a/src/actions/transformations/parity_zero_7bit.cc
+++ b/src/actions/transformations/parity_zero_7bit.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void ParityZero7bit::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
 
     input = reinterpret_cast<unsigned char *>
diff --git a/src/actions/transformations/parity_zero_7bit.h b/src/actions/transformations/parity_zero_7bit.h
index 647c7fa2..3dff4d33 100644
--- a/src/actions/transformations/parity_zero_7bit.h
+++ b/src/actions/transformations/parity_zero_7bit.h
@@ -34,8 +34,8 @@ class ParityZero7bit : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static bool inplace(unsigned char *input, uint64_t input_len);
 };
diff --git a/src/actions/transformations/remove_comments.cc b/src/actions/transformations/remove_comments.cc
index 44882e81..86b29320 100644
--- a/src/actions/transformations/remove_comments.cc
+++ b/src/actions/transformations/remove_comments.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void RemoveComments::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
 
     input = reinterpret_cast<unsigned char *>
diff --git a/src/actions/transformations/remove_comments.h b/src/actions/transformations/remove_comments.h
index 9fb33ea0..804a468f 100644
--- a/src/actions/transformations/remove_comments.h
+++ b/src/actions/transformations/remove_comments.h
@@ -35,8 +35,8 @@ class RemoveComments : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;;
+        ModSecString &in,
+        ModSecString &out) override;;
 };
 
 
diff --git a/src/actions/transformations/remove_comments_char.cc b/src/actions/transformations/remove_comments_char.cc
index e1bbf42a..db9c50b2 100644
--- a/src/actions/transformations/remove_comments_char.cc
+++ b/src/actions/transformations/remove_comments_char.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void RemoveCommentsChar::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int64_t i;
     out = in;
 
diff --git a/src/actions/transformations/remove_comments_char.h b/src/actions/transformations/remove_comments_char.h
index 31919925..53ac44ac 100644
--- a/src/actions/transformations/remove_comments_char.h
+++ b/src/actions/transformations/remove_comments_char.h
@@ -34,8 +34,8 @@ class RemoveCommentsChar : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/remove_nulls.cc b/src/actions/transformations/remove_nulls.cc
index 99f0ff14..5ee5fdf4 100644
--- a/src/actions/transformations/remove_nulls.cc
+++ b/src/actions/transformations/remove_nulls.cc
@@ -34,8 +34,8 @@ namespace transformations {
 
 
 void RemoveNulls::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int64_t i;
     out = in;
 
diff --git a/src/actions/transformations/remove_nulls.h b/src/actions/transformations/remove_nulls.h
index 452c93cc..00adf316 100644
--- a/src/actions/transformations/remove_nulls.h
+++ b/src/actions/transformations/remove_nulls.h
@@ -34,8 +34,8 @@ class RemoveNulls : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/remove_whitespace.cc b/src/actions/transformations/remove_whitespace.cc
index 19a30b97..7d758fad 100644
--- a/src/actions/transformations/remove_whitespace.cc
+++ b/src/actions/transformations/remove_whitespace.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void RemoveWhitespace::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     out = in;
     int64_t i = 0;
 
diff --git a/src/actions/transformations/remove_whitespace.h b/src/actions/transformations/remove_whitespace.h
index f4a41007..71119be1 100644
--- a/src/actions/transformations/remove_whitespace.h
+++ b/src/actions/transformations/remove_whitespace.h
@@ -34,8 +34,8 @@ class RemoveWhitespace : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/replace_comments.cc b/src/actions/transformations/replace_comments.cc
index a4f19489..25fdac9f 100644
--- a/src/actions/transformations/replace_comments.cc
+++ b/src/actions/transformations/replace_comments.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void ReplaceComments::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     uint64_t i, j, incomment;
 
     char *input = reinterpret_cast<char *>(
diff --git a/src/actions/transformations/replace_comments.h b/src/actions/transformations/replace_comments.h
index 80899cfe..c09c65a4 100644
--- a/src/actions/transformations/replace_comments.h
+++ b/src/actions/transformations/replace_comments.h
@@ -34,8 +34,8 @@ class ReplaceComments : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/replace_nulls.cc b/src/actions/transformations/replace_nulls.cc
index 5b54e24e..bcd28497 100644
--- a/src/actions/transformations/replace_nulls.cc
+++ b/src/actions/transformations/replace_nulls.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void ReplaceNulls::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int64_t i;
     out = in;
 
diff --git a/src/actions/transformations/replace_nulls.h b/src/actions/transformations/replace_nulls.h
index e9434a5c..544f256d 100644
--- a/src/actions/transformations/replace_nulls.h
+++ b/src/actions/transformations/replace_nulls.h
@@ -34,8 +34,8 @@ class ReplaceNulls : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/sha1.cc b/src/actions/transformations/sha1.cc
index 17bcc0c2..995922b9 100644
--- a/src/actions/transformations/sha1.cc
+++ b/src/actions/transformations/sha1.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void Sha1::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
 
     auto a = Utils::Sha1::digest(
             std::string(in.c_str(), in.size())
diff --git a/src/actions/transformations/sha1.h b/src/actions/transformations/sha1.h
index 02377e43..fce9aa75 100644
--- a/src/actions/transformations/sha1.h
+++ b/src/actions/transformations/sha1.h
@@ -34,8 +34,8 @@ class Sha1 : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/sql_hex_decode.cc b/src/actions/transformations/sql_hex_decode.cc
index 1420451a..da7fc301 100644
--- a/src/actions/transformations/sql_hex_decode.cc
+++ b/src/actions/transformations/sql_hex_decode.cc
@@ -42,8 +42,8 @@ namespace transformations {
 #endif
 
 void SqlHexDecode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
     int size = 0;
 
diff --git a/src/actions/transformations/sql_hex_decode.h b/src/actions/transformations/sql_hex_decode.h
index cb7617a6..7e0d4dd4 100644
--- a/src/actions/transformations/sql_hex_decode.h
+++ b/src/actions/transformations/sql_hex_decode.h
@@ -34,8 +34,8 @@ class SqlHexDecode : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int inplace(unsigned char *data, int len);
 
diff --git a/src/actions/transformations/transformation.cc b/src/actions/transformations/transformation.cc
index 5becd84c..f039c5ab 100644
--- a/src/actions/transformations/transformation.cc
+++ b/src/actions/transformations/transformation.cc
@@ -114,6 +114,7 @@ Transformation* Transformation::instantiate(std::string a) {
     return new Transformation(a);
 }
 
+
 }  // namespace transformations
 }  // namespace actions
 }  // namespace modsecurity
diff --git a/src/actions/transformations/transformation.h b/src/actions/transformations/transformation.h
index 8f11542d..9bedeb3f 100644
--- a/src/actions/transformations/transformation.h
+++ b/src/actions/transformations/transformation.h
@@ -32,12 +32,7 @@ class Transformation : public Action {
     explicit Transformation(const std::string& _action)
         : Action(_action, RunTimeBeforeMatchAttemptKind) { }
 
-    void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override {
-            // FIXME: this should be remove as soon as #1974 got fixed.
-            out.assign(in.c_str(), in.length());
-    }
+    virtual bool isNone() { return false; }
 
     static Transformation* instantiate(std::string a);
 };
diff --git a/src/actions/transformations/trim.cc b/src/actions/transformations/trim.cc
index dba82910..251d75df 100644
--- a/src/actions/transformations/trim.cc
+++ b/src/actions/transformations/trim.cc
@@ -31,27 +31,27 @@ namespace actions {
 namespace transformations {
 
 
-void Trim::ltrim(ModSecStackString *s) {
+void Trim::ltrim(ModSecString *s) {
     s->erase(s->begin(), std::find_if(s->begin(), s->end(),
         std::not1(std::ptr_fun<int, int>(std::isspace))));
 }
 
 
-void Trim::rtrim(ModSecStackString *s) {
+void Trim::rtrim(ModSecString *s) {
     s->erase(std::find_if(s->rbegin(), s->rend(),
         std::not1(std::ptr_fun<int, int>(std::isspace))).base(), s->end());
 }
 
 
-void Trim::trim(ModSecStackString *s) {
+void Trim::trim(ModSecString *s) {
     rtrim(s);
     ltrim(s);
 }
 
 
 void Trim::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     out = in;
     trim(&out);
 };
diff --git a/src/actions/transformations/trim.h b/src/actions/transformations/trim.h
index bfb76160..6a390fd6 100644
--- a/src/actions/transformations/trim.h
+++ b/src/actions/transformations/trim.h
@@ -34,12 +34,12 @@ class Trim : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
-    void ltrim(ModSecStackString *s);
-    void rtrim(ModSecStackString *s);
-    void trim(ModSecStackString *s);
+    void ltrim(ModSecString *s);
+    void rtrim(ModSecString *s);
+    void trim(ModSecString *s);
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/trim_left.cc b/src/actions/transformations/trim_left.cc
index 3451389b..bdf099e2 100644
--- a/src/actions/transformations/trim_left.cc
+++ b/src/actions/transformations/trim_left.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void TrimLeft::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     out = in;
     ltrim(&out);
 };
diff --git a/src/actions/transformations/trim_left.h b/src/actions/transformations/trim_left.h
index 91912921..02b40685 100644
--- a/src/actions/transformations/trim_left.h
+++ b/src/actions/transformations/trim_left.h
@@ -35,8 +35,8 @@ class TrimLeft : public Trim {
         : Trim(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/trim_right.cc b/src/actions/transformations/trim_right.cc
index ee968a90..91898e18 100644
--- a/src/actions/transformations/trim_right.cc
+++ b/src/actions/transformations/trim_right.cc
@@ -32,8 +32,8 @@ namespace transformations {
 
 
 void TrimRight::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     out = in;
     rtrim(&out);
 };
diff --git a/src/actions/transformations/trim_right.h b/src/actions/transformations/trim_right.h
index 7fa2d570..5300559d 100644
--- a/src/actions/transformations/trim_right.h
+++ b/src/actions/transformations/trim_right.h
@@ -35,8 +35,8 @@ class TrimRight : public Trim {
         : Trim(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/upper_case.cc b/src/actions/transformations/upper_case.cc
index 99100df0..2e6eaf24 100644
--- a/src/actions/transformations/upper_case.cc
+++ b/src/actions/transformations/upper_case.cc
@@ -28,8 +28,8 @@ namespace transformations {
 
 
 void UpperCase::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     std::locale loc;
     out.reserve(in.size());
     for (std::string::size_type i=0; i < in.size(); ++i) {
diff --git a/src/actions/transformations/upper_case.h b/src/actions/transformations/upper_case.h
index cf3de628..37c10444 100644
--- a/src/actions/transformations/upper_case.h
+++ b/src/actions/transformations/upper_case.h
@@ -36,8 +36,8 @@ class UpperCase : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/url_decode.cc b/src/actions/transformations/url_decode.cc
index 75ba798c..e5f32afd 100644
--- a/src/actions/transformations/url_decode.cc
+++ b/src/actions/transformations/url_decode.cc
@@ -33,8 +33,8 @@ namespace transformations {
 
 
 void UrlDecode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *val(NULL);
     int invalid_count = 0;
     int changed;
diff --git a/src/actions/transformations/url_decode.h b/src/actions/transformations/url_decode.h
index b39707a4..03535f2f 100644
--- a/src/actions/transformations/url_decode.h
+++ b/src/actions/transformations/url_decode.h
@@ -36,8 +36,8 @@ class UrlDecode : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 };
 
 }  // namespace transformations
diff --git a/src/actions/transformations/url_decode_uni.cc b/src/actions/transformations/url_decode_uni.cc
index 9855ae41..18326d24 100644
--- a/src/actions/transformations/url_decode_uni.cc
+++ b/src/actions/transformations/url_decode_uni.cc
@@ -39,8 +39,8 @@ namespace transformations {
 
 
 void UrlDecodeUni::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     unsigned char *input;
 
     input = reinterpret_cast<unsigned char *>
diff --git a/src/actions/transformations/url_decode_uni.h b/src/actions/transformations/url_decode_uni.h
index 4ffbcc6a..4b739919 100644
--- a/src/actions/transformations/url_decode_uni.h
+++ b/src/actions/transformations/url_decode_uni.h
@@ -35,8 +35,8 @@ class UrlDecodeUni : public Transformation {
         : Transformation(action) { }
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static int inplace(unsigned char *input, uint64_t input_len,
         Transaction *transaction);
diff --git a/src/actions/transformations/url_encode.cc b/src/actions/transformations/url_encode.cc
index 6bfc3463..aa722883 100644
--- a/src/actions/transformations/url_encode.cc
+++ b/src/actions/transformations/url_encode.cc
@@ -82,8 +82,8 @@ std::string UrlEncode::url_enc(const char *input,
 
 
 void UrlEncode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
     int changed;
 
     std::string ret = url_enc(in.c_str(), in.size(), &changed);
diff --git a/src/actions/transformations/url_encode.h b/src/actions/transformations/url_encode.h
index 85217bd4..d4d23e63 100644
--- a/src/actions/transformations/url_encode.h
+++ b/src/actions/transformations/url_encode.h
@@ -34,8 +34,8 @@ class UrlEncode : public Transformation {
         : Transformation(action) { };
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static std::string url_enc(const char *input,
         unsigned int input_len, int *changed);
diff --git a/src/actions/transformations/utf8_to_unicode.cc b/src/actions/transformations/utf8_to_unicode.cc
index d979be38..ab848f4e 100644
--- a/src/actions/transformations/utf8_to_unicode.cc
+++ b/src/actions/transformations/utf8_to_unicode.cc
@@ -34,8 +34,8 @@ namespace transformations {
 
 
 void Utf8ToUnicode::execute(Transaction *t,
-    ModSecStackString &in,
-    ModSecStackString &out) {
+    ModSecString &in,
+    ModSecString &out) {
 
     unsigned char *input;
     int changed = 0;
diff --git a/src/actions/transformations/utf8_to_unicode.h b/src/actions/transformations/utf8_to_unicode.h
index 5bb9bd15..ffc863bc 100644
--- a/src/actions/transformations/utf8_to_unicode.h
+++ b/src/actions/transformations/utf8_to_unicode.h
@@ -40,8 +40,8 @@ class Utf8ToUnicode : public Transformation {
 
 
     void execute(Transaction *t,
-        ModSecStackString &in,
-        ModSecStackString &out) override;
+        ModSecString &in,
+        ModSecString &out) override;
 
     static char *inplace(unsigned char *input, uint64_t input_len,
         int *changed);
diff --git a/src/actions/ver.cc b/src/actions/ver.cc
index e967b1c9..caf3d08b 100644
--- a/src/actions/ver.cc
+++ b/src/actions/ver.cc
@@ -21,6 +21,7 @@
 #include "modsecurity/actions/action.h"
 #include "modsecurity/transaction.h"
 #include "modsecurity/rule.h"
+#include "modsecurity/rule_with_actions.h"
 
 
 namespace modsecurity {
diff --git a/src/engine/lua.cc b/src/engine/lua.cc
index ca1d3ebe..ef99d701 100644
--- a/src/engine/lua.cc
+++ b/src/engine/lua.cc
@@ -439,8 +439,8 @@ std::string Lua::applyTransformations(lua_State *L, Transaction *t,
                     "t:" + std::string(name));
             // FIXME: transformation is not yet returning null.
             if (tfn) {
-                ModSecStackString in;
-                ModSecStackString out;
+                ModSecString in;
+                ModSecString out;
                 in.assign(newVar.c_str(), newVar.size());
                 tfn->execute(t, in, out);
                 newVar.assign(out.c_str(), out.size());
@@ -465,8 +465,8 @@ std::string Lua::applyTransformations(lua_State *L, Transaction *t,
 
         // FIXME: transformation is not yet returning null.
         if (tfn) {
-            ModSecStackString in;
-            ModSecStackString out;
+            ModSecString in;
+            ModSecString out;
             in.assign(newVar.c_str(), newVar.size());
             tfn->execute(t, in, out);
             newVar.assign(out.c_str(), out.size());
diff --git a/src/modsecurity.cc b/src/modsecurity.cc
index a4d691ac..2f70d470 100644
--- a/src/modsecurity.cc
+++ b/src/modsecurity.cc
@@ -305,8 +305,8 @@ int ModSecurity::processContentOffset(const char *content, size_t len,
 
     while (!trans.empty()) {
         modsecurity::actions::transformations::Transformation *t;
-        ModSecStackString in;
-        ModSecStackString out;
+        ModSecString in;
+        ModSecString out;
 
         yajl_gen_map_open(g);
         yajl_gen_string(g,
diff --git a/src/operators/detect_sqli.cc b/src/operators/detect_sqli.cc
index 232ef9f4..b79e0a0b 100644
--- a/src/operators/detect_sqli.cc
+++ b/src/operators/detect_sqli.cc
@@ -20,6 +20,8 @@
 
 #include "src/operators/operator.h"
 #include "others/libinjection/src/libinjection.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace operators {
diff --git a/src/operators/detect_xss.cc b/src/operators/detect_xss.cc
index a1d96845..c641ea5f 100644
--- a/src/operators/detect_xss.cc
+++ b/src/operators/detect_xss.cc
@@ -19,6 +19,7 @@
 
 #include "src/operators/operator.h"
 #include "others/libinjection/src/libinjection.h"
+#include "modsecurity/rule_with_actions.h"
 
 
 namespace modsecurity {
diff --git a/src/operators/pm.cc b/src/operators/pm.cc
index 5622df69..b673efac 100644
--- a/src/operators/pm.cc
+++ b/src/operators/pm.cc
@@ -28,6 +28,8 @@
 #include "src/operators/operator.h"
 #include "src/utils/acmp.h"
 #include "src/utils/string.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace operators {
diff --git a/src/operators/rbl.cc b/src/operators/rbl.cc
index 0936fff3..0628dc18 100644
--- a/src/operators/rbl.cc
+++ b/src/operators/rbl.cc
@@ -25,6 +25,8 @@
 
 #include "modsecurity/rules_set.h"
 #include "src/operators/operator.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace operators {
diff --git a/src/operators/rx.cc b/src/operators/rx.cc
index 84ca30af..cb3cec89 100644
--- a/src/operators/rx.cc
+++ b/src/operators/rx.cc
@@ -22,6 +22,8 @@
 #include "src/operators/operator.h"
 #include "modsecurity/rule.h"
 #include "modsecurity/rule_message.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace operators {
diff --git a/src/operators/verify_cc.cc b/src/operators/verify_cc.cc
index eef2aaea..8891cb14 100644
--- a/src/operators/verify_cc.cc
+++ b/src/operators/verify_cc.cc
@@ -21,6 +21,8 @@
 #include <vector>
 
 #include "src/operators/operator.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 #if PCRE_HAVE_JIT
 #define pcre_study_opt PCRE_STUDY_JIT_COMPILE
diff --git a/src/operators/verify_cpf.cc b/src/operators/verify_cpf.cc
index f5d5a140..edac33a9 100644
--- a/src/operators/verify_cpf.cc
+++ b/src/operators/verify_cpf.cc
@@ -19,6 +19,8 @@
 #include <list>
 
 #include "src/operators/operator.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace operators {
diff --git a/src/operators/verify_ssn.cc b/src/operators/verify_ssn.cc
index e65520a7..3a5a69d9 100644
--- a/src/operators/verify_ssn.cc
+++ b/src/operators/verify_ssn.cc
@@ -20,6 +20,8 @@
 #include <list>
 
 #include "src/operators/operator.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace operators {
diff --git a/src/operators/verify_svnr.cc b/src/operators/verify_svnr.cc
index f9f4174c..075c5989 100644
--- a/src/operators/verify_svnr.cc
+++ b/src/operators/verify_svnr.cc
@@ -9,6 +9,7 @@
 #include "modsecurity/rule_message.h"
 #include "modsecurity/rules_set_properties.h"
 
+#include "modsecurity/rule_with_actions.h"
 
 namespace modsecurity {
 namespace operators {
diff --git a/src/parser/seclang-parser.cc b/src/parser/seclang-parser.cc
index 8f7de4e0..f32e987a 100644
--- a/src/parser/seclang-parser.cc
+++ b/src/parser/seclang-parser.cc
@@ -2439,8 +2439,8 @@ namespace yy {
                 definedPhase = phase->m_phase;
                 secRuleDefinedPhase = phase->m_secRulesPhase;
                 delete phase;
-            } else if (a->action_kind == actions::Action::RunTimeOnlyIfMatchKind ||
-                a->action_kind == actions::Action::RunTimeBeforeMatchAttemptKind) {
+            } else if (a->m_actionKind == actions::Action::RunTimeOnlyIfMatchKind ||
+                a->m_actionKind == actions::Action::RunTimeBeforeMatchAttemptKind) {
                                 actions::transformations::None *none = dynamic_cast<actions::transformations::None *>(a);
                 if (none != NULL) {
                     driver.error(yystack_[2].location, "The transformation none is not suitable to be part of the SecDefaultActions");
diff --git a/src/parser/seclang-parser.yy b/src/parser/seclang-parser.yy
index b59401e8..89f52329 100644
--- a/src/parser/seclang-parser.yy
+++ b/src/parser/seclang-parser.yy
@@ -18,6 +18,8 @@ class Driver;
 }
 
 #include "modsecurity/rule_unconditional.h"
+#include "modsecurity/rule_with_operator.h"
+#include "modsecurity/rule_with_actions.h"
 #include "src/rule_script.h"
 
 #include "src/actions/accuracy.h"
@@ -1185,8 +1187,8 @@ expression:
                 definedPhase = phase->m_phase;
                 secRuleDefinedPhase = phase->m_secRulesPhase;
                 delete phase;
-            } else if (a->action_kind == actions::Action::RunTimeOnlyIfMatchKind ||
-                a->action_kind == actions::Action::RunTimeBeforeMatchAttemptKind) {
+            } else if (a->m_actionKind == actions::Action::RunTimeOnlyIfMatchKind ||
+                a->m_actionKind == actions::Action::RunTimeBeforeMatchAttemptKind) {
                                 actions::transformations::None *none = dynamic_cast<actions::transformations::None *>(a);
                 if (none != NULL) {
                     driver.error(@0, "The transformation none is not suitable to be part of the SecDefaultActions");
diff --git a/src/rule_script.h b/src/rule_script.h
index 2e4c2086..6375d8ee 100644
--- a/src/rule_script.h
+++ b/src/rule_script.h
@@ -32,6 +32,8 @@
 #include "src/actions/log_data.h"
 #include "src/actions/severity.h"
 #include "src/variables/variable.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 #ifndef SRC_RULE_SCRIPT_H_
 #define SRC_RULE_SCRIPT_H_
diff --git a/src/rule_with_actions.cc b/src/rule_with_actions.cc
index f4867646..0312d089 100644
--- a/src/rule_with_actions.cc
+++ b/src/rule_with_actions.cc
@@ -104,12 +104,7 @@ RuleWithActions::RuleWithActions(
 }
 
 void RuleWithActions::addDefaultAction(std::shared_ptr<actions::Action> a) {
-    if (a->action_kind == Action::ConfigurationKind) {
-        a->execute(this, NULL);
-        return;
-    }
-
-    if (a->action_kind == Action::ConfigurationKind) {
+    if (a->m_actionKind == Action::ConfigurationKind) {
         if (dynamic_cast<actions::Accuracy *>(a.get())) {
             actions::Accuracy *accuracy = dynamic_cast<actions::Accuracy *>(a.get());
             m_defaultAccuracy = accuracy->getAccuracy();
@@ -122,7 +117,7 @@ void RuleWithActions::addDefaultAction(std::shared_ptr<actions::Action> a) {
         return;
     }
 
-    if (a->action_kind == Action::RunTimeOnlyIfMatchKind) {
+    if (a->m_actionKind == Action::RunTimeOnlyIfMatchKind) {
         if (dynamic_cast<actions::Capture *>(a.get())) {
             m_defaultContainsCaptureAction = true;
         } else if (dynamic_cast<actions::MultiMatch *>(a.get())) {
@@ -163,7 +158,7 @@ void RuleWithActions::addDefaultAction(std::shared_ptr<actions::Action> a) {
 }
 
 void RuleWithActions::addAction(actions::Action *a) {
-    if (a->action_kind == Action::ConfigurationKind) {
+    if (a->m_actionKind == Action::ConfigurationKind) {
         if (dynamic_cast<actions::Accuracy *>(a)) {
             actions::Accuracy *accuracy = dynamic_cast<actions::Accuracy *>(a);
             m_accuracy = accuracy->getAccuracy();
@@ -177,7 +172,7 @@ void RuleWithActions::addAction(actions::Action *a) {
         return;
     }
 
-    if (a->action_kind == Action::RunTimeOnlyIfMatchKind) {
+    if (a->m_actionKind == Action::RunTimeOnlyIfMatchKind) {
         if (dynamic_cast<actions::Capture *>(a)) {
             m_containsCaptureAction = true;
             delete a;
@@ -281,7 +276,7 @@ void RuleWithActions::executeActionsAfterFullMatch(Transaction *trans) {
 
 #if 0
     for (auto &a : trans->m_rules->m_defaultActions[getPhase()]) {
-        if (a.get()->action_kind != actions::Action::RunTimeOnlyIfMatchKind) {
+        if (a.get()->m_actionKind != actions::Action::RunTimeOnlyIfMatchKind) {
             continue;
         }
         if (!a.get()->isDisruptive()) {
@@ -363,7 +358,7 @@ void RuleWithActions::executeTransformations(
     TransformationsResults &results) {
     int none = 0;
 
-    ModSecStackString ssin;
+    ModSecString ssin;
     ssin.assign(in.c_str());
 
     TransformationResult a = TransformationResult(&ssin);
@@ -374,9 +369,8 @@ void RuleWithActions::executeTransformations(
     std::shared_ptr<std::string> value =
         std::shared_ptr<std::string>(new std::string(in));
 
-
-    for (Action *action : getTransformationPtr()) {
-        if (action->m_isNone) {
+    for (Transformation *action : getTransformationPtr()) {
+        if (action->isNone()) {
             none++;
         }
     }
@@ -385,7 +379,7 @@ void RuleWithActions::executeTransformations(
         if (none == 0) {
             executeTransformation(trans, &results, t);
         }
-        if (t->m_isNone) {
+        if (t->isNone()) {
             none--;
         }
     }
@@ -398,7 +392,7 @@ void RuleWithActions::executeTransformations(
             continue;
         }
         Transformation *t = dynamic_cast<Transformation*>(b.second.get());
-        if (t->m_isNone) {
+        if (t->isNone()) {
             none++;
         }
     }
@@ -412,7 +406,7 @@ void RuleWithActions::executeTransformations(
         if (none == 0) {
             executeTransformation(trans, &results, t);
         }
-        if (t->m_isNone) {
+        if (t->isNone()) {
             none--;
         }
     }
@@ -446,11 +440,11 @@ void RuleWithActions::executeTransformation(
 
 void RuleWithActions::executeTransformation(
     Transaction *transaction,
-    ModSecStackString in,
+    ModSecString in,
     TransformationsResults *ret,
     Transformation *transformation) {
 
-    ModSecStackString out;
+    ModSecString out;
     transformation->execute(transaction, in, out);
 
     ms_dbg_a(transaction, 9, " T (" + std::to_string(ret->size() - 1) + ") " + \
diff --git a/src/rules.cc b/src/rules.cc
index 4666deb0..b35664fb 100644
--- a/src/rules.cc
+++ b/src/rules.cc
@@ -14,7 +14,7 @@
  */
 
 #include "modsecurity/rules.h"
-#include "src/rule_with_actions.h"
+#include "modsecurity/rule_with_actions.h"
 
 
 namespace modsecurity {
@@ -37,14 +37,14 @@ int Rules::append(Rules *from, const std::vector<int64_t> &ids, std::ostringstre
 }
 
 
-bool Rules::insert(std::shared_ptr<Rule> rule) {
+bool Rules::insert(const std::shared_ptr<Rule> &rule) {
     return insert(rule, nullptr, nullptr);
 }
 
 
 bool Rules::insert(std::shared_ptr<Rule> rule, const std::vector<int64_t> *ids, std::ostringstream *err) {
     RuleWithActions*r = dynamic_cast<RuleWithActions*>(rule.get());
-    if (r && ids != nullptr && err != nullptr
+    if (r && ids != nullptr
         && std::binary_search(ids->begin(), ids->end(), r->getId())) {
         if (err != NULL) {
             *err << "Rule id: " << std::to_string(r->getId()) \
@@ -57,22 +57,22 @@ bool Rules::insert(std::shared_ptr<Rule> rule, const std::vector<int64_t> *ids,
 }
 
 
-size_t Rules::size() {
+size_t Rules::size() const {
     return m_rules.size();
 }
 
 
-std::shared_ptr<Rule> Rules::operator[](int index) {
+std::shared_ptr<Rule> Rules::operator[](int index) const {
     return m_rules[index];
 }
 
 
-std::shared_ptr<Rule> Rules::at(int index) {
+std::shared_ptr<Rule> Rules::at(int index) const {
     return m_rules[index];
 }
 
 
-void Rules::dump() {
+void Rules::dump() const {
     for (int j = 0; j < m_rules.size(); j++) {
         std::cout << "    Rule ID: " << m_rules.at(j)->getReference();
         std::cout << "--" << m_rules.at(j) << std::endl;
diff --git a/src/rules_exceptions.cc b/src/rules_exceptions.cc
index 93b23a43..4259ac09 100644
--- a/src/rules_exceptions.cc
+++ b/src/rules_exceptions.cc
@@ -36,15 +36,15 @@ bool RulesExceptions::loadUpdateActionById(double id,
     std::string *error) {
 
     for (auto &a : *actions) {
-        if (a->action_kind == actions::Action::ConfigurationKind) {
+        if (a->m_actionKind == actions::Action::ConfigurationKind) {
             std::cout << "General failure, action: " << a->m_name;
             std::cout << " has not expected to be used with UpdateActionByID.";
             std::cout << std::endl;
-        } else if (a->action_kind
+        } else if (a->m_actionKind
             == actions::Action::RunTimeBeforeMatchAttemptKind) {
             m_action_pre_update_target_by_id.emplace(std::pair<double,
                 std::unique_ptr<actions::Action>>(id , std::move(a)));
-        } else if (a->action_kind == actions::Action::RunTimeOnlyIfMatchKind) {
+        } else if (a->m_actionKind == actions::Action::RunTimeOnlyIfMatchKind) {
             m_action_pos_update_target_by_id.emplace(std::pair<double,
                 std::unique_ptr<actions::Action>>(id , std::move(a)));
         } else {
diff --git a/src/run_time_string.cc b/src/run_time_string.cc
index 604467e8..a470f5e7 100644
--- a/src/run_time_string.cc
+++ b/src/run_time_string.cc
@@ -25,6 +25,7 @@
 #include "src/variables/highest_severity.h"
 #include "src/utils/string.h"
 #include "src/variables/variable.h"
+#include "modsecurity/rule_with_operator.h"
 
 
 namespace modsecurity {
diff --git a/src/variables/rule.h b/src/variables/rule.h
index b313b188..76d13a8c 100644
--- a/src/variables/rule.h
+++ b/src/variables/rule.h
@@ -24,7 +24,7 @@
 #include "src/actions/severity.h"
 #include "src/actions/log_data.h"
 #include "src/actions/msg.h"
-
+#include "modsecurity/rule_with_actions.h"
 
 namespace modsecurity {
 
diff --git a/src/variables/xml.cc b/src/variables/xml.cc
index 853db8f7..8e434c86 100644
--- a/src/variables/xml.cc
+++ b/src/variables/xml.cc
@@ -42,6 +42,8 @@
 #include "src/request_body_processor/xml.h"
 #include "modsecurity/actions/action.h"
 #include "src/actions/xmlns.h"
+#include "modsecurity/rule_with_actions.h"
+
 
 namespace modsecurity {
 namespace variables {
diff --git a/test/cppcheck_suppressions.txt b/test/cppcheck_suppressions.txt
index d7a54b78..9c5e829e 100644
--- a/test/cppcheck_suppressions.txt
+++ b/test/cppcheck_suppressions.txt
@@ -37,7 +37,7 @@ redundantAssignment:src/operators/pm.cc:94
 unmatchedSuppression:src/utils/geo_lookup.cc:82
 useInitializationList:src/utils/shared_files.h:87
 unmatchedSuppression:src/utils/msc_tree.cc
-functionStatic:headers/modsecurity/transaction.h:453
+functionStatic:headers/modsecurity/transaction.h:452
 duplicateBranch:src/audit_log/audit_log.cc:223
 unreadVariable:src/request_body_processor/multipart.cc:435
 stlcstrParam:src/audit_log/writer/parallel.cc:145
@@ -54,7 +54,7 @@ syntaxError:src/transaction.cc:62
 noConstructor:src/variables/variable.h:152
 duplicateBranch:src/request_body_processor/multipart.cc:93
 knownConditionTrueFalse:src/operators/validate_url_encoding.cc:77
-knownConditionTrueFalse:src/operators/verify_svnr.cc:87
+knownConditionTrueFalse:src/operators/verify_svnr.cc:88
 
 
 noExplicitConstructor:seclang-parser.hh
diff --git a/test/unit/unit.cc b/test/unit/unit.cc
index 9973ca27..40b47dfb 100644
--- a/test/unit/unit.cc
+++ b/test/unit/unit.cc
@@ -90,8 +90,8 @@ void perform_unit_test(ModSecurityTest<UnitTest> *test, UnitTest *t,
         }
         delete op;
     } else if (t->type == "tfn") {
-        modsecurity::ModSecStackString in;
-        modsecurity::ModSecStackString out;
+        modsecurity::ModSecString in;
+        modsecurity::ModSecString out;
         std::string ret;
         in.assign(t->input.c_str(), t->input.size());
         Transformation *tfn = Transformation::instantiate("t:" + t->name);