diff --git a/libraries/PID/PID.cpp b/libraries/PID/PID.cpp
index 47a03ebf5d..98dcbfd6c8 100644
--- a/libraries/PID/PID.cpp
+++ b/libraries/PID/PID.cpp
@@ -8,88 +8,88 @@
 #include "PID.h"
 
 const AP_Param::GroupInfo PID::var_info[] PROGMEM = {
-	AP_GROUPINFO("P",    0, PID, _kp, 0),
-	AP_GROUPINFO("I",    1, PID, _ki, 0),
-	AP_GROUPINFO("D",    2, PID, _kd, 0),
-	AP_GROUPINFO("IMAX", 3, PID, _imax, 0),
-	AP_GROUPEND
+    AP_GROUPINFO("P",    0, PID, _kp, 0),
+    AP_GROUPINFO("I",    1, PID, _ki, 0),
+    AP_GROUPINFO("D",    2, PID, _kd, 0),
+    AP_GROUPINFO("IMAX", 3, PID, _imax, 0),
+    AP_GROUPEND
 };
 
 int32_t
 PID::get_pid(int32_t error, float scaler)
 {
-	uint32_t tnow = millis();
-	uint32_t dt = tnow - _last_t;
-	float output		= 0;
- 	float delta_time;
+    uint32_t tnow = millis();
+    uint32_t dt = tnow - _last_t;
+    float output            = 0;
+    float delta_time;
 
-	if (_last_t == 0 || dt > 1000) {
-		dt = 0;
-	}
-	_last_t = tnow;
+    if (_last_t == 0 || dt > 1000) {
+        dt = 0;
+    }
+    _last_t = tnow;
 
-	delta_time = (float)dt / 1000.0;
+    delta_time = (float)dt / 1000.0;
 
-	// Compute proportional component
-	output += error * _kp;
+    // Compute proportional component
+    output += error * _kp;
 
-	// Compute derivative component if time has elapsed
-	if ((fabs(_kd) > 0) && (dt > 0)) {
-		float derivative = (error - _last_error) / delta_time;
+    // Compute derivative component if time has elapsed
+    if ((fabs(_kd) > 0) && (dt > 0)) {
+        float derivative = (error - _last_error) / delta_time;
 
-		// discrete low pass filter, cuts out the
-		// high frequency noise that can drive the controller crazy
-		float RC = 1/(2*M_PI*_fCut);
-		derivative = _last_derivative +
-		        (delta_time / (RC + delta_time)) * (derivative - _last_derivative);
+        // discrete low pass filter, cuts out the
+        // high frequency noise that can drive the controller crazy
+        float RC = 1/(2*M_PI*_fCut);
+        derivative = _last_derivative +
+                     (delta_time / (RC + delta_time)) * (derivative - _last_derivative);
 
-		// update state
-		_last_error 		= error;
-		_last_derivative    = derivative;
+        // update state
+        _last_error             = error;
+        _last_derivative    = derivative;
 
-		// add in derivative component
-		output 				+= _kd * derivative;
-	}
+        // add in derivative component
+        output                          += _kd * derivative;
+    }
 
-	// scale the P and D components
-	output *= scaler;
+    // scale the P and D components
+    output *= scaler;
 
-	// Compute integral component if time has elapsed
-	if ((fabs(_ki) > 0) && (dt > 0)) {
-		_integrator 		+= (error * _ki) * scaler * delta_time;
-		if (_integrator < -_imax) {
-			_integrator = -_imax;
-		} else if (_integrator > _imax) {
-			_integrator = _imax;
-		}
-		output 				+= _integrator;
-	}
+    // Compute integral component if time has elapsed
+    if ((fabs(_ki) > 0) && (dt > 0)) {
+        _integrator             += (error * _ki) * scaler * delta_time;
+        if (_integrator < -_imax) {
+            _integrator = -_imax;
+        } else if (_integrator > _imax) {
+            _integrator = _imax;
+        }
+        output                          += _integrator;
+    }
 
-	return output;
+    return output;
 }
 
 void
 PID::reset_I()
 {
-	_integrator = 0;
-	_last_error = 0;
-	_last_derivative = 0;
+    _integrator = 0;
+    _last_error = 0;
+    _last_derivative = 0;
 }
 
 void
 PID::load_gains()
 {
-	_kp.load();
-	_ki.load();
-	_kd.load();
-	_imax.load();
+    _kp.load();
+    _ki.load();
+    _kd.load();
+    _imax.load();
 }
 
 void
 PID::save_gains()
 {
-	_kp.save();
-	_ki.save();
-	_kd.save();
-	_imax.save();
+    _kp.save();
+    _ki.save();
+    _kd.save();
+    _imax.save();
 }