diff --git a/libraries/Filter/examples/Derivative/Derivative.pde b/libraries/Filter/examples/Derivative/Derivative.pde
index ffe94ee161..4f4ee2cfcb 100644
--- a/libraries/Filter/examples/Derivative/Derivative.pde
+++ b/libraries/Filter/examples/Derivative/Derivative.pde
@@ -35,7 +35,7 @@ mavlink_system_t mavlink_system;
 
 FastSerialPort0(Serial);        // FTDI/console
 
-DerivativeFilter<float,float,7> derivative;
+DerivativeFilter<float,7> derivative;
 
 // setup routine
 void setup()
@@ -58,7 +58,7 @@ void loop()
 	delay(50);
 	float t = millis()*1.0e-3;
 	float s = sin(t);
-	//s += noise();
+	s += noise();
 	uint32_t t1 = micros();
 	float output = derivative.apply(s, t1) * 1.0e6;
 	uint32_t t2 = micros();