diff --git a/ArduCopter/ArduCopter.pde b/ArduCopter/ArduCopter.pde
index 7eeab480f2..417ffe7d47 100644
--- a/ArduCopter/ArduCopter.pde
+++ b/ArduCopter/ArduCopter.pde
@@ -1040,9 +1040,6 @@ static void medium_loop()
 			#if HIL_MODE != HIL_MODE_ATTITUDE					// don't execute in HIL mode
 				if(g.compass_enabled){
 					if (compass.read()) {
-                        // Calculate heading
-                        Matrix3f m = ahrs.get_dcm_matrix();
-                        compass.calculate(m);
                         compass.null_offsets();
                     }
 				}
diff --git a/ArduCopter/Log.pde b/ArduCopter/Log.pde
index b1202d1127..e404df91ea 100644
--- a/ArduCopter/Log.pde
+++ b/ArduCopter/Log.pde
@@ -744,7 +744,7 @@ static void Log_Write_Attitude()
 	DataFlash.WriteInt((int)ahrs.pitch_sensor);		// 4
 	DataFlash.WriteInt(g.rc_4.control_in);			// 5
 	DataFlash.WriteInt((uint16_t)ahrs.yaw_sensor);	// 6
-	DataFlash.WriteInt((uint16_t)(wrap_360(ToDeg(compass.heading)*100)));	// 7
+	DataFlash.WriteInt(0);	// 7 (this used to be compass.heading)
 
 	DataFlash.WriteByte(END_BYTE);
 }
diff --git a/ArduCopter/sensors.pde b/ArduCopter/sensors.pde
index db90c58100..9620e7033f 100644
--- a/ArduCopter/sensors.pde
+++ b/ArduCopter/sensors.pde
@@ -42,7 +42,6 @@ static void init_compass()
         return;
     }
     ahrs.set_compass(&compass);
-    compass.null_offsets_enable();
 }
 
 static void init_optflow()
diff --git a/ArduCopter/setup.pde b/ArduCopter/setup.pde
index e7c6665bfb..85632f7095 100644
--- a/ArduCopter/setup.pde
+++ b/ArduCopter/setup.pde
@@ -719,13 +719,13 @@ setup_mag_offset(uint8_t argc, const Menu::arg *argv)
 	int _max[3] = {0,0,0};
 
 	compass.read();
-	compass.calculate(0,0);	// roll = 0, pitch = 0
 
 	while(1){
 		delay(50);
+        float heading;
 
 		compass.read();
-		compass.calculate(0,0);	// roll = 0, pitch = 0
+		heading = compass.calculate_heading(0,0);	// roll = 0, pitch = 0
 
 		if(compass.mag_x < _min[0])	_min[0] = compass.mag_x;
 		if(compass.mag_y < _min[1])	_min[1] = compass.mag_y;
@@ -744,7 +744,7 @@ setup_mag_offset(uint8_t argc, const Menu::arg *argv)
 		// display all to user
 		Serial.printf_P(PSTR("Heading: %u, \t (%d, %d, %d), (%4.4f, %4.4f, %4.4f)\n"),
 
-				(uint16_t)(wrap_360(ToDeg(compass.heading) * 100)) /100,
+				(uint16_t)(wrap_360(ToDeg(heading) * 100)) /100,
 
 				compass.mag_x,
 				compass.mag_y,
diff --git a/ArduCopter/test.pde b/ArduCopter/test.pde
index f2a76d6d68..129bce0921 100644
--- a/ArduCopter/test.pde
+++ b/ArduCopter/test.pde
@@ -334,7 +334,6 @@ test_radio(uint8_t argc, const Menu::arg *argv)
 				if(medium_loopCounter == 5){
                     Matrix3f m = dcm.get_dcm_matrix();
 					compass.read();		 				// Read magnetometer
-					compass.calculate(m);
                     compass.null_offsets();
 					medium_loopCounter = 0;
 				}
@@ -552,8 +551,6 @@ test_imu(uint8_t argc, const Menu::arg *argv)
 
 				if(g.compass_enabled){
 					compass.read();		 				// Read magnetometer
-                    Matrix3f m = dcm.get_dcm_matrix();
-					compass.calculate(m);
                     compass.null_offsets();
 				}
 			}
@@ -954,10 +951,10 @@ test_mag(uint8_t argc, const Menu::arg *argv)
 			while(1){
 				delay(100);
 				if (compass.read()) {
-					compass.calculate(ahrs.get_dcm_matrix());
+					float heading = compass.calculate_heading(ahrs.get_dcm_matrix());
 					Vector3f maggy = compass.get_offsets();
 					Serial.printf_P(PSTR("Heading: %ld, XYZ: %d, %d, %d\n"),
-									(wrap_360(ToDeg(compass.heading) * 100)) /100,
+									(wrap_360(ToDeg(heading) * 100)) /100,
 									compass.mag_x,
 									compass.mag_y,
 									compass.mag_z);