diff --git a/headers/modsecurity/rules.h b/headers/modsecurity/rules.h
index 6d01e0ea..71afebe0 100644
--- a/headers/modsecurity/rules.h
+++ b/headers/modsecurity/rules.h
@@ -99,7 +99,7 @@ extern "C" {
 
 Rules *msc_create_rules_set();
 void msc_rules_dump(Rules *rules);
-int msc_rules_merge(Rules *rules_dst, Rules *rules_from);
+int msc_rules_merge(Rules *rules_dst, Rules *rules_from, const char **error);
 int msc_rules_add_remote(Rules *rules, const char *key, const char *uri,
     const char **error);
 int msc_rules_add_file(Rules *rules, const char *file, const char **error);
diff --git a/src/rules.cc b/src/rules.cc
index 0e406d9b..3faf1740 100644
--- a/src/rules.cc
+++ b/src/rules.cc
@@ -277,8 +277,12 @@ extern "C" void msc_rules_dump(Rules *rules) {
 
 
 extern "C" int msc_rules_merge(Rules *rules_dst,
-    Rules *rules_from) {
-    return rules_dst->merge(rules_from);
+    Rules *rules_from, const char **error) {
+    int ret = rules_dst->merge(rules_from);
+    if (ret < 0) {
+        *error = strdup(rules_dst->getParserError().c_str());
+    }
+    return ret;
 }