1 files changed, 1 insertions, 1 deletions
diff --git a/tool/ifchange b/tool/ifchange
index c54b8fbb03..5695e5a9b8 100755
--- a/tool/ifchange
+++ b/tool/ifchange
@@ -4,7 +4,7 @@
 set -e
 timestamp=
 keepsuffix=
-until [ "$0" = 0 ]; do
+until [ $# -eq 0 ]; do
     case "$1" in
 	--timestamp)
 	    timestamp=.