X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/puzzles/blobdiff_plain/4d08de49555f22d1fcf2d9977a19591a0f465b2d..de3b0e332712c81307a7800808b6d13d2c5cec93:/fifteen.c

diff --git a/fifteen.c b/fifteen.c
index c076350..20ceb4b 100644
--- a/fifteen.c
+++ b/fifteen.c
@@ -76,7 +76,7 @@ static game_params *dup_params(game_params *params)
 static void decode_params(game_params *ret, char const *string)
 {
     ret->w = ret->h = atoi(string);
-    while (*string && isdigit(*string)) string++;
+    while (*string && isdigit((unsigned char)*string)) string++;
     if (*string == 'x') {
         string++;
         ret->h = atoi(string);