diff --git a/headers/modsecurity/rules_properties.h b/headers/modsecurity/rules_properties.h
index 73fab218..80021a2d 100644
--- a/headers/modsecurity/rules_properties.h
+++ b/headers/modsecurity/rules_properties.h
@@ -54,6 +54,15 @@ class ConfigInt {
     ConfigInt() : m_set(false), m_value(0) { }
     bool m_set;
     int m_value;
+
+    void merge(ConfigInt *from) {
+        if (m_set == true || from->m_set == false) {
+            return;
+        }
+        m_set = true;
+        m_value = from->m_value;
+        return;
+    }
 };
 
 
@@ -62,6 +71,15 @@ class ConfigDouble {
     ConfigDouble() : m_set(false), m_value(0) { }
     bool m_set;
     double m_value;
+
+    void merge(ConfigDouble *from) {
+        if (m_set == true || from->m_set == false) {
+            return;
+        }
+        m_set = true;
+        m_value = from->m_value;
+        return;
+    }
 };
 
 
@@ -70,6 +88,15 @@ class ConfigString {
     ConfigString() : m_set(false), m_value("") { }
     bool m_set;
     std::string m_value;
+
+    void merge(ConfigString *from) {
+        if (m_set == true || from->m_set == false) {
+            return;
+        }
+        m_set = true;
+        m_value = from->m_value;
+        return;
+    }
 };
 
 
@@ -341,15 +368,8 @@ class RulesProperties {
             to->m_tmpSaveUploadedFiles = from->m_tmpSaveUploadedFiles;
         }
 
-        if (from->m_requestBodyLimit.m_set == true) {
-            to->m_requestBodyLimit.m_value = from->m_requestBodyLimit.m_value;
-            to->m_requestBodyLimit.m_set = true;
-        }
-
-        if (from->m_responseBodyLimit.m_set == true) {
-            to->m_responseBodyLimit.m_value = from->m_responseBodyLimit.m_value;
-            to->m_responseBodyLimit.m_set = true;
-        }
+        to->m_requestBodyLimit.merge(&from->m_requestBodyLimit);
+        to->m_responseBodyLimit.merge(&from->m_responseBodyLimit);
 
         if (from->m_requestBodyLimitAction != PropertyNotSetBodyLimitAction) {
             to->m_requestBodyLimitAction = from->m_requestBodyLimitAction;
@@ -359,45 +379,18 @@ class RulesProperties {
             to->m_responseBodyLimitAction = from->m_responseBodyLimitAction;
         }
 
-        if (from->m_uploadFileLimit.m_set == true) {
-            to->m_uploadFileLimit.m_value = from->m_uploadFileLimit.m_value;
-            to->m_uploadFileLimit.m_set = true;
-        }
+        to->m_uploadFileLimit.merge(&from->m_uploadFileLimit);
+        to->m_uploadFileMode.merge(&from->m_uploadFileMode);
+        to->m_uploadDirectory.merge(&from->m_uploadDirectory);
+        to->m_uploadTmpDirectory.merge(&from->m_uploadTmpDirectory);
 
-        if (from->m_uploadFileMode.m_set == true) {
-            to->m_uploadFileMode.m_value = from->m_uploadFileMode.m_value;
-            to->m_uploadFileMode.m_set = true;
-        }
+        to->m_secArgumentSeparator.merge(&from->m_secArgumentSeparator);
 
-        if (from->m_uploadDirectory.m_set == true) {
-            to->m_uploadDirectory.m_value = from->m_uploadDirectory.m_value;
-            to->m_uploadDirectory.m_set = true;
-        }
-
-        if (from->m_uploadTmpDirectory.m_set == true) {
-            to->m_uploadTmpDirectory.m_value = \
-                from->m_uploadTmpDirectory.m_value;
-            to->m_uploadTmpDirectory.m_set = true;
-        }
-
-        if (from->m_secArgumentSeparator.m_set == true) {
-            to->m_secArgumentSeparator.m_value = \
-                from->m_secArgumentSeparator.m_value;
-            to->m_secArgumentSeparator.m_set = true;
-        }
-
-        if (from->m_secWebAppId.m_set == true) {
-            to->m_secWebAppId.m_value = \
-                from->m_secWebAppId.m_value;
-            to->m_secWebAppId.m_set = true;
-        }
+        to->m_secWebAppId.merge(&from->m_secWebAppId);
 
         to->m_unicodeMapTable.merge(&from->m_unicodeMapTable);
 
-        if (from->m_httpblKey.m_set == true) {
-            to->m_httpblKey.m_value = from->m_httpblKey.m_value;
-            to->m_httpblKey.m_set = from->m_httpblKey.m_set;
-        }
+        to->m_httpblKey.merge(&from->m_httpblKey);
 
         to->m_exceptions.merge(&from->m_exceptions);