diff --git a/DDCore/include/DD4hep/detail/Grammar_unparsed.h b/DDCore/include/DD4hep/detail/Grammar_unparsed.h
index f7e3058290169be4f846ffa35fb38eea4e55d62a..eca64cb92dc47ceff19096896d29538611080b9b 100644
--- a/DDCore/include/DD4hep/detail/Grammar_unparsed.h
+++ b/DDCore/include/DD4hep/detail/Grammar_unparsed.h
@@ -45,7 +45,7 @@ namespace dd4hep {
 
   /// Standarsd constructor
   template <typename TYPE> const BasicGrammar& BasicGrammar::instance()  {
-    static Grammar<TYPE> s_gr();
+    static Grammar<TYPE> s_gr;
     return s_gr;
   }
 }