diff --git a/include/SimCore/Identifier.hpp b/include/SimCore/Identifier.hpp
index 8abb1ca..cd73102 100644
--- a/include/SimCore/Identifier.hpp
+++ b/include/SimCore/Identifier.hpp
@@ -18,7 +18,7 @@ namespace SimCore {
             * @brief constructs an object 
             * 
             */
-            Identifier(std::uint32_t parent,std::uint32_t number,bool external) ;
+            Identifier(std::uint32_t parent,std::uint32_t number,bool external = false) ;
 
             /**
             * @brief constructs the ID out of an string