1 files changed, 1 insertions, 1 deletions
diff --git a/locale.c b/locale.c
index 8dabc7d2..5b3e66b9 100644
--- a/locale.c
+++ b/locale.c
@@ -535,7 +535,7 @@ locale_setblanks ()
 
   for (x = 0; x < sh_syntabsiz; x++)
     {
-      if (isblank (x))
+      if (isblank ((unsigned char)x))
 	sh_syntaxtab[x] |= CSHBRK|CBLANK;
       else if (member (x, shell_break_chars))
 	{