diff --git a/libraries/Filter/DerivativeFilter.h b/libraries/Filter/DerivativeFilter.h
index ad71e0aa7d..031ac5469d 100644
--- a/libraries/Filter/DerivativeFilter.h
+++ b/libraries/Filter/DerivativeFilter.h
@@ -17,31 +17,32 @@
 #include <Filter.h>
 #include <FilterWithBuffer.h>
 
-// 1st parameter <T> is the type of data being filtered.  
+// 1st parameter <T> is the type of data being filtered.
 // 2nd parameter <FILTER_SIZE> is the number of elements in the filter
 template <class T, uint8_t FILTER_SIZE>
 class DerivativeFilter : public FilterWithBuffer<T,FILTER_SIZE>
 {
-  public:
-	// constructor
-	DerivativeFilter() : FilterWithBuffer<T,FILTER_SIZE>() {};
+public:
+    // constructor
+    DerivativeFilter() : FilterWithBuffer<T,FILTER_SIZE>() {
+    };
 
-	// update - Add a new raw value to the filter, but don't recalculate
-	virtual void update(T sample, uint32_t timestamp);
+    // update - Add a new raw value to the filter, but don't recalculate
+    virtual void        update(T sample, uint32_t timestamp);
 
-	// return the derivative value
-	virtual float slope(void);
+    // return the derivative value
+    virtual float        slope(void);
 
-	// reset - clear the filter
-	virtual void reset();
+    // reset - clear the filter
+    virtual void        reset();
 
-  private:
-    bool _new_data;
-    float _last_slope;
+private:
+    bool            _new_data;
+    float           _last_slope;
 
     // microsecond timestamps for samples. This is needed
     // to cope with non-uniform time spacing of the data
-    uint32_t _timestamps[FILTER_SIZE];
+    uint32_t        _timestamps[FILTER_SIZE];
 };
 
 typedef DerivativeFilter<float,5> DerivativeFilterFloat_Size5;