@@ -57,11 +57,11 @@
 		/*
 		 * '+' is also listed in RFC 1738, however, '+' is sometimes
 		 * interpreted as space in HTTP. Therefore always escape it to
 		 * make sure it's always interpreted correctly.
 		 */
-		if (!(c & 0x80) && (isalnum(c) || strchr(allowed, c) != NULL))
+		if (of_ascii_isalnum(c) || strchr(allowed, c) != NULL)
 			retCString[i++] = c;
 		else {
 			unsigned char high, low;
 
 			high = c >> 4;