diff --git a/libraries/AP_IMU/AP_IMU_Shim.h b/libraries/AP_IMU/AP_IMU_Shim.h
index be02e27565..89ab56d13f 100644
--- a/libraries/AP_IMU/AP_IMU_Shim.h
+++ b/libraries/AP_IMU/AP_IMU_Shim.h
@@ -3,10 +3,43 @@
 /// @file	AP_IMU_Shim.h
 /// @brief	IMU shim driver, used when the IMU data is coming from somewhere else.
 
-#ifndef AP_IMU_Shim_h
#define AP_IMU_Shim_h

class AP_IMU_Shim : public IMU
{
public:
	AP_IMU_Shim(void) {}

	/// @name IMU protocol
	//@{
	virtual void	init(Start_style style) {}
+#ifndef AP_IMU_Shim_h
+#define AP_IMU_Shim_h
+
+class AP_IMU_Shim : public IMU
+{
+public:
+	AP_IMU_Shim(void) {}
+
+	/// @name IMU protocol
+	//@{
+	virtual void	init(Start_style style) {}
 	virtual void	init_accel(Start_style style) {};
 	virtual void	init_gyro(Start_style style) {};
-	virtual bool	update(void) {
		bool updated = _updated;
-		_updated = false;
		return updated;
	}
	//@}

	/// Set the gyro vector.  ::update will return
	/// true once after this call.
	///
	/// @param	v		The new gyro vector.
	///
	void		set_gyro(Vector3f v) { _gyro = v; _updated = true; }

	/// Set the accelerometer vector.  ::update will return
	/// true once after this call.
	///
	/// @param	v		The new accelerometer vector.
	///
	void		set_accel(Vector3f v) { _accel = v; _updated = true; }

private:
	/// set true when new data is delivered
	bool		_updated;
};
+	virtual bool	update(void) {
+		bool updated = _updated;
+		_updated = false;
+		return updated;
+	}
+	//@}
+
+	/// Set the gyro vector.  ::update will return
+	/// true once after this call.
+	///
+	/// @param	v		The new gyro vector.
+	///
+	void		set_gyro(Vector3f v) { _gyro = v; _updated = true; }
+
+	/// Set the accelerometer vector.  ::update will return
+	/// true once after this call.
+	///
+	/// @param	v		The new accelerometer vector.
+	///
+	void		set_accel(Vector3f v) { _accel = v; _updated = true; }
+
+private:
+	/// set true when new data is delivered
+	bool		_updated;
+};
 
 #endif