diff --git a/libraries/AP_GPS/AP_GPS_Shim.h b/libraries/AP_GPS/AP_GPS_Shim.h
index 41646a0d6e..a99ab6e9ab 100644
--- a/libraries/AP_GPS/AP_GPS_Shim.h
+++ b/libraries/AP_GPS/AP_GPS_Shim.h
@@ -14,15 +14,33 @@
 
 #include <GPS.h>
 
-class AP_GPS_Shim : public GPS
{
+class AP_GPS_Shim : public GPS
+{
 public:
-	AP_GPS_Shim() : GPS(NULL) {}
+	AP_GPS_Shim() : GPS(NULL) {}
+
 	virtual void init(void) {};
-	virtual bool read(void) {
		bool updated = _updated;
		_updated = false;
		return _updated;
	}
+	virtual bool read(void) {
+		bool updated = _updated;
+		_updated = false;
+		return _updated;
+	}
 
 	/// Set-and-mark-updated macro for the public member variables; each instance
 	/// defines a member function set_<variable>(<type>)
-	///
#define __GPS_SHIM_SET(__type, __name) void set_##__name(__type v) { __name = v; _updated = true; }
	__GPS_SHIM_SET(long, time);
	__GPS_SHIM_SET(long, latitude);
	__GPS_SHIM_SET(long, longitude);
	__GPS_SHIM_SET(long, altitude);
	__GPS_SHIM_SET(long, ground_speed);
	__GPS_SHIM_SET(long, ground_course);
	__GPS_SHIM_SET(long, speed_3d);
	__GPS_SHIM_SET(int, hdop);
#undef __GPS_SHIM_SET

private:
+	///
+#define __GPS_SHIM_SET(__type, __name) void set_##__name(__type v) { __name = v; _updated = true; }
+	__GPS_SHIM_SET(long, time);
+	__GPS_SHIM_SET(long, latitude);
+	__GPS_SHIM_SET(long, longitude);
+	__GPS_SHIM_SET(long, altitude);
+	__GPS_SHIM_SET(long, ground_speed);
+	__GPS_SHIM_SET(long, ground_course);
+	__GPS_SHIM_SET(long, speed_3d);
+	__GPS_SHIM_SET(int, hdop);
+#undef __GPS_SHIM_SET
+
+private:
 	bool	_updated;		///< set anytime a member is updated, cleared when read() returns true
 };