diff --git a/include_all/hardware/audio_amplifier.h b/include_all/hardware/audio_amplifier.h
index 4b6f634..39589e2 100644
--- a/include_all/hardware/audio_amplifier.h
+++ b/include_all/hardware/audio_amplifier.h
@@ -136,7 +136,8 @@
     /**
      * Amplifier calibration
      */
-    int (*calibrate)(void *adev);
+    int (*calibrate)(struct amplifier_device *device,
+        void *adev);
 } amplifier_device_t;
 
 typedef struct amplifier_module {