diff --git a/orm/src/main/java/com/zfoo/orm/codec/MapCodec.java b/orm/src/main/java/com/zfoo/orm/codec/MapCodec.java
index 8801917a..533d440d 100644
--- a/orm/src/main/java/com/zfoo/orm/codec/MapCodec.java
+++ b/orm/src/main/java/com/zfoo/orm/codec/MapCodec.java
@@ -1,3 +1,14 @@
+/*
+ * Copyright (C) 2020 The zfoo Authors
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
 package com.zfoo.orm.codec;
 
 import org.bson.BsonReader;
diff --git a/orm/src/main/java/com/zfoo/orm/codec/MapCodecProvider.java b/orm/src/main/java/com/zfoo/orm/codec/MapCodecProvider.java
index b05b6cfb..3de16e79 100644
--- a/orm/src/main/java/com/zfoo/orm/codec/MapCodecProvider.java
+++ b/orm/src/main/java/com/zfoo/orm/codec/MapCodecProvider.java
@@ -1,3 +1,14 @@
+/*
+ * Copyright (C) 2020 The zfoo Authors
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
 package com.zfoo.orm.codec;
 
 
diff --git a/orm/src/main/java/com/zfoo/orm/codec/MapKeyCodecEnum.java b/orm/src/main/java/com/zfoo/orm/codec/MapKeyCodecEnum.java
index 99ba5363..2a06b1dd 100644
--- a/orm/src/main/java/com/zfoo/orm/codec/MapKeyCodecEnum.java
+++ b/orm/src/main/java/com/zfoo/orm/codec/MapKeyCodecEnum.java
@@ -1,3 +1,14 @@
+/*
+ * Copyright (C) 2020 The zfoo Authors
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
 package com.zfoo.orm.codec;
 
 import java.util.Arrays;