diff --git a/collector/devstat_freebsd.c b/collector/devstat_freebsd.c
index c3352e2c..43539b77 100644
--- a/collector/devstat_freebsd.c
+++ b/collector/devstat_freebsd.c
@@ -1,3 +1,16 @@
+// Copyright 2017 The Prometheus 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.
+
 // +build !nodevstat
 
 #include <devstat.h>
diff --git a/collector/devstat_freebsd.h b/collector/devstat_freebsd.h
index 4ee1c62d..b0cd4a1e 100644
--- a/collector/devstat_freebsd.h
+++ b/collector/devstat_freebsd.h
@@ -1,3 +1,16 @@
+// Copyright 2017 The Prometheus 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.
+
 #include <devstat.h>
 #include <fcntl.h>
 #include <libgeom.h>