diff --git a/pom.xml b/pom.xml
index ac6f852..2b47db2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -14,6 +14,7 @@
described by Hugo Krawczyk. It is special as it supports 2 Phases: Extract and Expand.
https://github.com/patrickfav/hkdf
+ 2017
3.1.0
diff --git a/src/main/java/at/favre/lib/crypto/HKDF.java b/src/main/java/at/favre/lib/crypto/HKDF.java
index d45e4f1..0524dc6 100644
--- a/src/main/java/at/favre/lib/crypto/HKDF.java
+++ b/src/main/java/at/favre/lib/crypto/HKDF.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2017 Patrick Favre-Bulle
+ *
+ * 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 at.favre.lib.crypto;
import javax.crypto.Mac;
diff --git a/src/main/java/at/favre/lib/crypto/HkdfMacFactory.java b/src/main/java/at/favre/lib/crypto/HkdfMacFactory.java
index 882a47e..d2b43ea 100644
--- a/src/main/java/at/favre/lib/crypto/HkdfMacFactory.java
+++ b/src/main/java/at/favre/lib/crypto/HkdfMacFactory.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2017 Patrick Favre-Bulle
+ *
+ * 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 at.favre.lib.crypto;
import javax.crypto.Mac;