diff --git a/lang/cem/libcc.ansi/string/memcmp.c b/lang/cem/libcc.ansi/string/memcmp.c
index 93b97e72e..f7295f071 100644
--- a/lang/cem/libcc.ansi/string/memcmp.c
+++ b/lang/cem/libcc.ansi/string/memcmp.c
@@ -9,13 +9,13 @@
 int
 memcmp(const void *s1, const void *s2, size_t n)
 {
-	register const char *p1 = s1, *p2 = s2;
+	register const unsigned char *p1 = s1, *p2 = s2;
 
 	if (n) {
 		n++;
 		while (--n > 0) {
 			if (*p1++ == *p2++) continue;
-			return (unsigned char) *--p1 - (unsigned char) *--p2;
+			return *--p1 - *--p2;
 		}
 	}
 	return 0;