diff --git a/src/xkbmisc.c b/src/xkbmisc.c
index 2f9b532e6..8be8dd508 100644
--- a/src/xkbmisc.c	
+++ b/src/xkbmisc.c
@@ -688,7 +688,9 @@ XkbNameMatchesPattern(char *name, char *ptrn)
 _X_HIDDEN int
 _XkbStrCaseCmp(char *str1, char *str2)
 {
-    const u_char *us1 = (const u_char *) str1, *us2 = (const u_char *) str2;
+    typedef unsigned char u_char;
+    const u_char *us1 = (const u_char *) str1;
+    const u_char *us2 = (const u_char *) str2;
 
     while (tolower(*us1) == tolower(*us2)) {
         if (*us1++ == '\0')