diff --git a/src/operators/contains.cc b/src/operators/contains.cc
index 91de6d78..afcb31b4 100644
--- a/src/operators/contains.cc
+++ b/src/operators/contains.cc
@@ -26,7 +26,7 @@ bool Contains::evaluate(Transaction *transaction, const std::string &input) {
     std::string p = MacroExpansion::expand(param, transaction);
     bool contains = input.find(p) != std::string::npos;
 
-    if (contains) {
+    if (contains && transaction) {
         transaction->m_matched.push_back(p);
     }
 
diff --git a/src/operators/pm.cc b/src/operators/pm.cc
index 2a8a2f70..351429fe 100644
--- a/src/operators/pm.cc
+++ b/src/operators/pm.cc
@@ -77,7 +77,7 @@ bool Pm::evaluate(Transaction *transaction, const std::string &input) {
     const char *match = NULL;
 
     rc = acmp_process_quick(&pt, &match, input.c_str(), input.length());
-    if (rc == 1) {
+    if (rc == 1 && transaction) {
         transaction->m_matched.push_back(std::string(match));
     }
 
diff --git a/src/operators/rx.cc b/src/operators/rx.cc
index 1d13c882..59a561af 100644
--- a/src/operators/rx.cc
+++ b/src/operators/rx.cc
@@ -29,8 +29,14 @@ namespace operators {
 bool Rx::evaluate(Transaction *transaction, const std::string& input) {
     SMatch match;
 
+    if (m_param.empty()) {
+        return true;
+    }
+
     if (regex_search(input, &match, *m_re) && match.size() >= 1) {
-        transaction->m_matched.push_back(match.match);
+        if (transaction) {
+            transaction->m_matched.push_back(match.match);
+        }
         return true;
     }