diff --git a/t/09_create_function.t b/t/09_create_function.t
index c09e310..d8f7d94 100644
--- a/t/09_create_function.t
+++ b/t/09_create_function.t
@@ -45,7 +45,7 @@ sub return_null {
 
 sub my_defined {
 #        warn("defined($_[0])\n");
-        return defined $_[0];
+        return defined $_[0] ? 1 : 0;
 }
 
 sub noop {