diff --git a/libraries/AP_IMU/AP_IMU_Shim.h b/libraries/AP_IMU/AP_IMU_Shim.h
index 727f8b16fc..8bb692e236 100644
--- a/libraries/AP_IMU/AP_IMU_Shim.h
+++ b/libraries/AP_IMU/AP_IMU_Shim.h
@@ -15,7 +15,8 @@ public:
 
 	/// @name IMU protocol
 	//@{
-    virtual void	init(Start_style style = COLD_START, void (*callback)(unsigned long t) = delay) {};
+    virtual void	init(Start_style style = COLD_START, void (*callback)(unsigned long t) = delay,
+						 AP_PeriodicProcess *scheduler = NULL) {};
 	virtual void	init_accel(void (*callback)(unsigned long t) = delay) {};
 	virtual void	init_gyro(void (*callback)(unsigned long t) = delay) {};
 	virtual bool	update(void) {