diff --git a/alib2abstraction/src/core/type_util.cpp b/alib2abstraction/src/core/type_util.cpp
index 9a65d0eb9af6bac6cc8f2a89e2299db1bcce6c39..d184c2414a2f01e089d6aef8c1d23f6fc58eac2d 100644
--- a/alib2abstraction/src/core/type_util.cpp
+++ b/alib2abstraction/src/core/type_util.cpp
@@ -119,7 +119,7 @@ std::string type_util < std::string >::normalize ( std::string arg ) {
 	return arg;
 }
 
-std::unique_ptr < type_details_base > type_util < std::string >::type ( std::string ) {
+std::unique_ptr < type_details_base > type_util < std::string >::type ( const std::string & ) {
 	return std::make_unique < type_details_type > ( "std::string" );
 }
 
diff --git a/alib2abstraction/src/core/type_util.hpp b/alib2abstraction/src/core/type_util.hpp
index 80bc6838c3401780b46a814c8701c0111ccdf19c..4a1ab3c8d2ab285a5d64ca9c6690c322afa5e896 100644
--- a/alib2abstraction/src/core/type_util.hpp
+++ b/alib2abstraction/src/core/type_util.hpp
@@ -80,7 +80,7 @@ struct type_util < std::string > {
 
 	static std::string normalize ( std::string arg );
 
-	static std::unique_ptr < type_details_base > type ( std::string arg );
+	static std::unique_ptr < type_details_base > type ( const std::string & arg );
 };
 
 template < >