diff --git a/experimental/devices/mpu9250/accelerometer/accelerometer.go b/experimental/devices/mpu9250/accelerometer/accelerometer.go
index ab0feee..34d867c 100644
--- a/experimental/devices/mpu9250/accelerometer/accelerometer.go
+++ b/experimental/devices/mpu9250/accelerometer/accelerometer.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The Periph Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
 package accelerometer
 
 // Valid accelerator values.
diff --git a/experimental/devices/mpu9250/reg/reg.go b/experimental/devices/mpu9250/reg/reg.go
index 769f5b3..5ae6fe9 100644
--- a/experimental/devices/mpu9250/reg/reg.go
+++ b/experimental/devices/mpu9250/reg/reg.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The Periph Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
 package reg
 
 // Unsorted mix of register addresses, commands and constants.
diff --git a/experimental/devices/mpu9250/spi.go b/experimental/devices/mpu9250/spi.go
index 713e352..444b4f3 100644
--- a/experimental/devices/mpu9250/spi.go
+++ b/experimental/devices/mpu9250/spi.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The Periph Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
 package mpu9250
 
 import (