diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
index 0e30e6e43b0c..18fbbb679851 100644
--- a/arch/s390/lib/string.c
+++ b/arch/s390/lib/string.c
@@ -246,14 +246,13 @@ EXPORT_SYMBOL(strcmp);
 #ifdef __HAVE_ARCH_STRRCHR
 char *strrchr(const char *s, int c)
 {
-       size_t len = __strend(s) - s;
+	ssize_t len = __strend(s) - s;
 
-       if (len)
-	       do {
-		       if (s[len] == (char) c)
-			       return (char *) s + len;
-	       } while (--len > 0);
-       return NULL;
+	do {
+		if (s[len] == (char)c)
+			return (char *)s + len;
+	} while (--len >= 0);
+	return NULL;
 }
 EXPORT_SYMBOL(strrchr);
 #endif