diff --git a/src/racket/src/syntax.c b/src/racket/src/syntax.c
index 955ad50723..f3b197934f 100644
--- a/src/racket/src/syntax.c
+++ b/src/racket/src/syntax.c
@@ -6852,7 +6852,7 @@ static Scheme_Object *unmarshal_mark(Scheme_Object *_a, Scheme_Unmarshal_Tables
   return n;
 }
 
-#if 1 
+#if 0 
 # define return_NULL return (printf("%d\n", __LINE__), NULL)
 #else
 # define return_NULL return NULL