diff --git a/ArduCopterMega/ArduCopterMega.pde b/ArduCopterMega/ArduCopterMega.pde
index a29d8e50c0..f521e7edfc 100644
--- a/ArduCopterMega/ArduCopterMega.pde
+++ b/ArduCopterMega/ArduCopterMega.pde
@@ -172,6 +172,7 @@ static AP_Int8                *flight_modes = &g.flight_mode1;
 	AP_GPS_HIL              g_gps_driver(NULL);
 
 #elif HIL_MODE == HIL_MODE_ATTITUDE
+	AP_ADC_HIL              adc;
 	AP_DCM_HIL              dcm;
 	AP_GPS_HIL              g_gps_driver(NULL);
 	AP_Compass_HIL          compass; // never used
@@ -1569,4 +1570,4 @@ static void auto_throttle()
 
 	//Serial.printf("wp:%d, \te:%d \tt%d \t%d\n", (int)next_WP.alt, (int)altitude_error, nav_throttle, g.rc_3.servo_out);
 }
-
+