diff --git a/libraries/AP_Math/quaternion.h b/libraries/AP_Math/quaternion.h
index f1932dbc29..d56bb91cf2 100644
--- a/libraries/AP_Math/quaternion.h
+++ b/libraries/AP_Math/quaternion.h
@@ -15,34 +15,41 @@
 class Quaternion
 {
 public:
-	float q1, q2, q3, q4;
+    float        q1, q2, q3, q4;
 
-	// constructor creates a quaternion equivalent
-	// to roll=0, pitch=0, yaw=0
-	Quaternion() { q1 = 1; q2 = q3 = q4 = 0; }
+    // constructor creates a quaternion equivalent
+    // to roll=0, pitch=0, yaw=0
+    Quaternion() {
+        q1 = 1; q2 = q3 = q4 = 0;
+    }
 
-	// setting constructor
-	Quaternion(const float _q1, const float _q2, const float _q3, const float _q4):
-	q1(_q1), q2(_q2), q3(_q3), q4(_q4) {}
+    // setting constructor
+    Quaternion(const float _q1, const float _q2, const float _q3, const float _q4) :
+        q1(_q1), q2(_q2), q3(_q3), q4(_q4) {
+    }
 
-	// function call operator
-	void operator ()(const float _q1, const float _q2, const float _q3, const float _q4)
-	{ q1 = _q1; q2 = _q2; q3 = _q3; q4 = _q4; }
+    // function call operator
+    void operator        ()(const float _q1, const float _q2, const float _q3, const float _q4)
+    {
+        q1 = _q1; q2 = _q2; q3 = _q3; q4 = _q4;
+    }
 
-	// check if any elements are NAN
-	bool is_nan(void)
-	{   return isnan(q1) || isnan(q2) || isnan(q3) || isnan(q4); }
+    // check if any elements are NAN
+    bool        is_nan(void)
+    {
+        return isnan(q1) || isnan(q2) || isnan(q3) || isnan(q4);
+    }
 
-	// return the rotation matrix equivalent for this quaternion
-	void rotation_matrix(Matrix3f &m);
+    // return the rotation matrix equivalent for this quaternion
+    void        rotation_matrix(Matrix3f &m);
 
-	// convert a vector from earth to body frame
-	void earth_to_body(Vector3f &v);
+    // convert a vector from earth to body frame
+    void        earth_to_body(Vector3f &v);
 
     // create a quaternion from Euler angles
-	void from_euler(float roll, float pitch, float yaw);
+    void        from_euler(float roll, float pitch, float yaw);
 
     // create eulers from a quaternion
-	void to_euler(float *roll, float *pitch, float *yaw);
+    void        to_euler(float *roll, float *pitch, float *yaw);
 };
 #endif // QUATERNION_H