1 files changed, 2 insertions, 1 deletions
diff --git a/dir.c b/dir.c
index d783c64..c6c542c 100644
--- a/dir.c
+++ b/dir.c
@@ -159,7 +159,8 @@ vms_hash (name)
 
   while (*name)
     {
-      h = (h << 4) + (isupper (*name) ? tolower (*name) : *name);
+      unsigned char uc = *name;
+      h = (h << 4) + (isupper (uc) ? tolower (uc) : uc);
       name++;
       g = h & 0xf0000000;
       if (g)