1 files changed, 1 insertions, 1 deletions
diff --git a/liblali.c b/liblali.c
index 674df77..5683bb3 100644
--- a/liblali.c
+++ b/liblali.c
@@ -1517,7 +1517,7 @@ static char *stdlib = LISP(
 
   (defun listp (x) (not (atom x)))
 
-  (defun zerop (x) (not (! x +0)))
+  (defun zerop (x) (not (dif x +0)))
 
   (defmacro and args
     (fill ((ap args) t)