diff --git a/implementations/GNUProlog/parser.prolog b/implementations/GNUProlog/parser.prolog
index 9efcebb..8aec286 100644
--- a/implementations/GNUProlog/parser.prolog
+++ b/implementations/GNUProlog/parser.prolog
@@ -168,4 +168,4 @@ assert_def(Symbol, Body) :-
         assertz(def(Symbol, Body))
     ) ; true.
 
-joydef("enstacken stack [clear] dip").
\ No newline at end of file
+:- initialization(joy_def("enstacken stack [clear] dip")).