diff --git a/libraries/AP_Compass/AP_Compass_HIL.cpp b/libraries/AP_Compass/AP_Compass_HIL.cpp
index fa674223c7..edf1aff396 100644
--- a/libraries/AP_Compass/AP_Compass_HIL.cpp
+++ b/libraries/AP_Compass/AP_Compass_HIL.cpp
@@ -1,3 +1,4 @@
+/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 /*
  *       AP_Compass_HIL.cpp - Arduino Library for HIL model of HMC5843 I2C Magnetometer
  *       Code by James Goppert. DIYDrones.com
@@ -17,21 +18,21 @@ extern const AP_HAL::HAL& hal;
 // constructor
 AP_Compass_HIL::AP_Compass_HIL() : Compass() 
 {
-        product_id = AP_COMPASS_TYPE_HIL;
-	_setup_earth_field();
+    product_id = AP_COMPASS_TYPE_HIL;
+    _setup_earth_field();
 }
 
 // setup _Bearth
 void AP_Compass_HIL::_setup_earth_field(void)
 {
-	// assume a earth field strength of 400
-        _Bearth(400, 0, 0);
-
-        // rotate _Bearth for inclination and declination. -66 degrees
-	// is the inclination in Canberra, Australia
-        Matrix3f R;
-	R.from_euler(0, ToRad(66), _declination.get());
-        _Bearth = R * _Bearth;
+    // assume a earth field strength of 400
+    _Bearth(400, 0, 0);
+	
+    // rotate _Bearth for inclination and declination. -66 degrees
+    // is the inclination in Canberra, Australia
+    Matrix3f R;
+    R.from_euler(0, ToRad(66), _declination.get());
+    _Bearth = R * _Bearth;
 }
 
 // Public Methods //////////////////////////////////////////////////////////////
@@ -68,35 +69,35 @@ bool AP_Compass_HIL::read()
 //
 void AP_Compass_HIL::setHIL(float roll, float pitch, float yaw)
 {
-	Matrix3f R;
+    Matrix3f R;
 
-        // create a rotation matrix for the given attitude
-        R.from_euler(roll, pitch, yaw);
+    // create a rotation matrix for the given attitude
+    R.from_euler(roll, pitch, yaw);
 
-	if (_last_declination != _declination.get()) {
-		_setup_earth_field();
-		_last_declination = _declination.get();
-	}
+    if (_last_declination != _declination.get()) {
+        _setup_earth_field();
+        _last_declination = _declination.get();
+    }
 
-        // convert the earth frame magnetic vector to body frame, and
-        // apply the offsets
-        _hil_mag = R.mul_transpose(_Bearth);
-	_hil_mag -= Vector3f(MAG_OFS_X, MAG_OFS_Y, MAG_OFS_Z);
+    // convert the earth frame magnetic vector to body frame, and
+    // apply the offsets
+    _hil_mag = R.mul_transpose(_Bearth);
+    _hil_mag -= Vector3f(MAG_OFS_X, MAG_OFS_Y, MAG_OFS_Z);
 
-	// apply default board orientation for this compass type. This is
-	// a noop on most boards
-	_hil_mag.rotate(MAG_BOARD_ORIENTATION);
+    // apply default board orientation for this compass type. This is
+    // a noop on most boards
+    _hil_mag.rotate(MAG_BOARD_ORIENTATION);
 
-	// add user selectable orientation
-	_hil_mag.rotate((enum Rotation)_orientation.get());
+    // add user selectable orientation
+    _hil_mag.rotate((enum Rotation)_orientation.get());
 
-	// and add in AHRS_ORIENTATION setting
-	_hil_mag.rotate(_board_orientation);
+    // and add in AHRS_ORIENTATION setting
+    _hil_mag.rotate(_board_orientation);
 
-	healthy = true;
+    healthy = true;
 }
 
 void AP_Compass_HIL::accumulate(void)
 {
-	// nothing to do
+    // nothing to do
 }