diff --git a/lisp/simple.el b/lisp/simple.el
index eb4f7a3f6db..61d031d211b 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1324,7 +1324,7 @@ specifies the value of ERROR-BUFFER."
 					     (list buffer error-file)
 					   buffer)
 					 nil shell-command-switch command)))
-	  (setq success (zerop exit-status))
+	  (setq success (and exit-status (zerop exit-status)))
 	  ;; Report the amount of output.
 	  (let ((lines (save-excursion
 			 (set-buffer buffer)