diff --git a/src/pqueue.c b/src/pqueue.c
index cb59c13ec..9d3c09787 100644
--- a/src/pqueue.c
+++ b/src/pqueue.c
@@ -3,6 +3,28 @@
  *
  * This file is part of libgit2, distributed under the GNU GPL v2 with
  * a Linking Exception. For full terms see the included COPYING file.
+ *
+ * This file is based on a modified version of the priority queue found
+ * in the Apache project and libpqueue library.
+ * 
+ * https://github.com/vy/libpqueue
+ * 
+ * Original file notice:
+ * 
+ * Copyright 2010 Volkan Yazici <volkan.yazici@gmail.com>
+ * Copyright 2006-2010 The Apache Software Foundation
+ *
+ * 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.
  */
 
 #include "common.h"
diff --git a/src/pqueue.h b/src/pqueue.h
index a3e1edd1d..ad9c38f14 100644
--- a/src/pqueue.h
+++ b/src/pqueue.h
@@ -1,8 +1,30 @@
 /*
- * Copyright (C) 2009-2012 the libgit2 contributors
+ * Copyright (C) 2009-2013 the libgit2 contributors
  *
  * This file is part of libgit2, distributed under the GNU GPL v2 with
  * a Linking Exception. For full terms see the included COPYING file.
+ * 
+ * This file is based on a modified version of the priority queue found
+ * in the Apache project and libpqueue library.
+ * 
+ * https://github.com/vy/libpqueue
+ * 
+ * Original file notice:
+ * 
+ * Copyright 2010 Volkan Yazici <volkan.yazici@gmail.com>
+ * Copyright 2006-2010 The Apache Software Foundation
+ *
+ * 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.
  */
 
 #ifndef INCLUDE_pqueue_h__