diff --git a/lib/roken/clz.c b/lib/roken/clz.c
index 301ab2778..1a36234f1 100644
--- a/lib/roken/clz.c
+++ b/lib/roken/clz.c
@@ -2,15 +2,23 @@
  * Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip.
  * All rights reserved.
  *
- * Licensed under the MIT License (the "License"); you may not use this file except
- * in compliance with the License. You may obtain a copy of the License at
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
  *
- * http://opensource.org/licenses/MIT
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
  *
- * Unless required by applicable law or agreed to in writing, software distributed
- * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
- * CONDITIONS OF ANY KIND, either express or implied. See the License for the
- * specific language governing permissions and limitations under the License.
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
  */
 
 #include <config.h>