diff --git a/ArduCopter/ArduCopter.pde b/ArduCopter/ArduCopter.pde
index 10337c505c..f757600dde 100644
--- a/ArduCopter/ArduCopter.pde
+++ b/ArduCopter/ArduCopter.pde
@@ -80,6 +80,7 @@ http://code.google.com/p/ardupilot-mega/downloads/list
 #include <AP_OpticalFlow.h> // Optical Flow library
 #include <Filter.h>			// Filter library
 #include <ModeFilter.h>		// Mode Filter from Filter library
+#include <AverageFilter.h>	// Mode Filter from Filter library
 #include <AP_Relay.h>		// APM relay
 #include <GCS_MAVLink.h>    // MAVLink GCS definitions
 #include <memcheck.h>
@@ -269,7 +270,7 @@ GCS_MAVLINK	gcs3;
 // SONAR selection
 ////////////////////////////////////////////////////////////////////////////////
 //
-ModeFilterInt16 sonar_mode_filter(5,2);
+ModeFilterInt16_Size5 sonar_mode_filter(2);
 #if CONFIG_SONAR == ENABLED
 	#if CONFIG_SONAR_SOURCE == SONAR_SOURCE_ADC
 	AP_AnalogSource_ADC sonar_analog_source( &adc, CONFIG_SONAR_SOURCE_ADC_CHANNEL, 0.25);