1 files changed, 1 insertions, 1 deletions
diff --git a/bin/ean13 b/bin/ean13
index 6fd125a..35e3686 100755
--- a/bin/ean13
+++ b/bin/ean13
@@ -15,7 +15,7 @@ do
 #printf >&2 'v: %s : cs=%d f=%d\n' "$v" $checksum $factor
 done
 if [[ ${#1} -eq 12 ]]
-then	echo "$1"$((10-checksum%10))
+then	echo "$1"$(((10-checksum%10)%10))
 else	[[ $((10-checksum%10)) -eq ${1:12} ]] || exit
 fi
 shift