diff --git a/src/script_opt/CPP/DeclFunc.cc b/src/script_opt/CPP/DeclFunc.cc
index c96530a16f..cdc95b5f2f 100644
--- a/src/script_opt/CPP/DeclFunc.cc
+++ b/src/script_opt/CPP/DeclFunc.cc
@@ -69,7 +69,7 @@ void CPPCompile::CreateFunction(const FuncTypePtr& ft, const ProfileFunc* pf, co
 
 	func_index[fname] = cast;
 
-	if ( casting_index.count(cast) == 0 )
+	if ( ! l && casting_index.count(cast) == 0 )
 		{
 		casting_index[cast] = func_casting_glue.size();