diff --git a/headers/modsecurity/anchored_set_variable_translation_proxy.h b/headers/modsecurity/anchored_set_variable_translation_proxy.h
index da0601bf..f90b9f24 100644
--- a/headers/modsecurity/anchored_set_variable_translation_proxy.h
+++ b/headers/modsecurity/anchored_set_variable_translation_proxy.h
@@ -47,7 +47,7 @@ class AnchoredSetVariableTranslationProxy {
                 VariableValue *newVariableValue = new VariableValue(name, &l->at(i)->getKey(), &l->at(i)->getKey());
                 const VariableValue *oldVariableValue = l->at(i);
                 l->at(i) = newVariableValue;
-                for (auto &oldOrigin : oldVariableValue->getOrigin()) {
+                for (const auto &oldOrigin : oldVariableValue->getOrigin()) {
                     std::unique_ptr<VariableOrigin> newOrigin(new VariableOrigin);
                     newOrigin->m_length = oldVariableValue->getKey().size();
                     newOrigin->m_offset = oldOrigin->m_offset - oldVariableValue->getKey().size() - 1;
diff --git a/headers/modsecurity/variable_value.h b/headers/modsecurity/variable_value.h
index f7871776..a9a15a7b 100644
--- a/headers/modsecurity/variable_value.h
+++ b/headers/modsecurity/variable_value.h
@@ -62,7 +62,7 @@ class VariableValue {
         m_keyWithCollection(o->m_keyWithCollection),
         m_value(o->m_value)
     {
-        for (auto &i : o->m_orign) {
+        for (const auto &i : o->m_orign) {
             std::unique_ptr<VariableOrigin> origin(new VariableOrigin());
             origin->m_offset = i->m_offset;
             origin->m_length = i->m_length;
diff --git a/src/actions/ctl/rule_remove_by_id.cc b/src/actions/ctl/rule_remove_by_id.cc
index e76a3119..eaaef220 100644
--- a/src/actions/ctl/rule_remove_by_id.cc
+++ b/src/actions/ctl/rule_remove_by_id.cc
@@ -30,7 +30,7 @@ bool RuleRemoveById::init(std::string *error) {
     std::string what(m_parser_payload, 15, m_parser_payload.size() - 15);
     bool added = false;
     std::vector<std::string> toRemove = utils::string::ssplit(what, ' ');
-    for (std::string &a : toRemove) {
+    for (const std::string &a : toRemove) {
         std::string b = modsecurity::utils::string::parserSanitizer(a);
         if (b.size() == 0) {
             continue;
diff --git a/src/audit_log/audit_log.cc b/src/audit_log/audit_log.cc
index 307819f0..1be8a47b 100644
--- a/src/audit_log/audit_log.cc
+++ b/src/audit_log/audit_log.cc
@@ -289,7 +289,7 @@ bool AuditLog::saveIfRelevant(Transaction *transaction, int parts) {
         return true;
     }
 
-    for (RuleMessage &i : transaction->m_rulesMessages) {
+    for (const RuleMessage &i : transaction->m_rulesMessages) {
         if (i.m_noAuditLog == false) {
             saveAnyway = true;
             break;
diff --git a/src/rule_message.cc b/src/rule_message.cc
index 496fe7ca..97d8f8b1 100644
--- a/src/rule_message.cc
+++ b/src/rule_message.cc
@@ -38,7 +38,7 @@ std::string RuleMessage::_details(const RuleMessage *rm) {
     msg.append(" [maturity \"" + std::to_string(rm->m_maturity) + "\"]");
     msg.append(" [accuracy \"" + std::to_string(rm->m_accuracy) + "\"]");
 
-    for (auto &a : rm->m_tags) {
+    for (const auto &a : rm->m_tags) {
         msg.append(" [tag \"" + utils::string::toHexIfNeeded(a, true) + "\"]");
     }
 
diff --git a/src/rule_with_operator.cc b/src/rule_with_operator.cc
index d218f14b..94d0f9a4 100644
--- a/src/rule_with_operator.cc
+++ b/src/rule_with_operator.cc
@@ -228,7 +228,7 @@ bool RuleWithOperator::evaluate(Transaction *trans,
 
 
     // FIXME: Make a class runTimeException to handle this cases.
-    for (auto &i : trans->m_ruleRemoveById) {
+    for (const auto &i : trans->m_ruleRemoveById) {
         if (m_ruleId != i) {
             continue;
         }
@@ -236,7 +236,7 @@ bool RuleWithOperator::evaluate(Transaction *trans,
             " was skipped due to a ruleRemoveById action...");
         return true;
     }
-    for (auto &i : trans->m_ruleRemoveByIdRange) {
+    for (const auto &i : trans->m_ruleRemoveByIdRange) {
         if (!(i.first <= m_ruleId && i.second >= m_ruleId)) {
             continue;
         }
diff --git a/src/rules_exceptions.cc b/src/rules_exceptions.cc
index 2c22d16f..68ded8b6 100644
--- a/src/rules_exceptions.cc
+++ b/src/rules_exceptions.cc
@@ -122,7 +122,7 @@ bool RulesExceptions::loadUpdateTargetById(double id,
 bool RulesExceptions::load(const std::string &a, std::string *error) {
     bool added = false;
     std::vector<std::string> toRemove = utils::string::ssplit(a, ' ');
-    for (std::string &r : toRemove) {
+    for (const std::string &r : toRemove) {
         std::string b = modsecurity::utils::string::parserSanitizer(r);
         if (b.size() == 0) {
             continue;
diff --git a/src/rules_set.cc b/src/rules_set.cc
index 40f1f950..84e7974e 100644
--- a/src/rules_set.cc
+++ b/src/rules_set.cc
@@ -162,7 +162,7 @@ int RulesSet::evaluate(int phase, Transaction *t) {
             }
             bool remove_rule = false;
             if (ruleWithActions && m_exceptions.m_remove_rule_by_msg.empty() == false) {
-                for (auto &z : m_exceptions.m_remove_rule_by_msg) {
+                for (const auto &z : m_exceptions.m_remove_rule_by_msg) {
                     if (ruleWithActions->containsMsg(z, t) == true) {
                         ms_dbg_a(t, 9, "Skipped rule id '" \
                             + ruleWithActions->getReference() \
@@ -177,7 +177,7 @@ int RulesSet::evaluate(int phase, Transaction *t) {
             }
 
             if (ruleWithActions && m_exceptions.m_remove_rule_by_tag.empty() == false) {
-                for (auto &z : m_exceptions.m_remove_rule_by_tag) {
+                for (const auto &z : m_exceptions.m_remove_rule_by_tag) {
                     if (ruleWithActions->containsTag(z, t) == true) {
                         ms_dbg_a(t, 9, "Skipped rule id '" \
                             + ruleWithActions->getReference() \
@@ -193,7 +193,7 @@ int RulesSet::evaluate(int phase, Transaction *t) {
 
 
             if (ruleWithActions) {
-                for (auto &z : t->m_ruleRemoveByTag) {
+                for (const auto &z : t->m_ruleRemoveByTag) {
                     if (ruleWithActions->containsTag(z, t) == true) {
                         ms_dbg_a(t, 9, "Skipped rule id '" \
                             + ruleWithActions->getReference() \
diff --git a/src/transaction.cc b/src/transaction.cc
index c294d7f3..0c98b49c 100644
--- a/src/transaction.cc
+++ b/src/transaction.cc
@@ -1242,7 +1242,7 @@ int Transaction::processResponseBody() {
         return true;
     }
 
-    std::set<std::string> &bi = \
+    const std::set<std::string> &bi = \
         m_rules->m_responseBodyTypeToBeInspected.m_value;
     auto t = bi.find(m_variableResponseContentType.m_value);
     if (t == bi.end()
diff --git a/src/variables/remote_user.cc b/src/variables/remote_user.cc
index a6c6816b..078a88fb 100644
--- a/src/variables/remote_user.cc
+++ b/src/variables/remote_user.cc
@@ -69,7 +69,7 @@ void RemoteUser::evaluate(Transaction *transaction,
     var = new VariableValue(&l2->at(0)->getKeyWithCollection(),
         &transaction->m_variableRemoteUser);
 
-    for (auto &i : l2->at(0)->getOrigin()) {
+    for (const auto &i : l2->at(0)->getOrigin()) {
         std::unique_ptr<VariableOrigin> origin(new VariableOrigin());
         origin->m_offset = i->m_offset;
         origin->m_length = i->m_length;
diff --git a/src/variables/variable.cc b/src/variables/variable.cc
index 0a50d322..740548cb 100644
--- a/src/variables/variable.cc
+++ b/src/variables/variable.cc
@@ -83,7 +83,7 @@ std::string operator+(const std::string &a, Variable *v) {
 
 std::string operator+(const std::string &a, Variables *v) {
     std::string test;
-    for (auto &b : *v) {
+    for (const auto &b : *v) {
         if (test.empty()) {
             test = std::string("") + b;
         } else {