diff --git a/ArduCopter/Copter.h b/ArduCopter/Copter.h
index 7727338abc..1dd4d988d8 100644
--- a/ArduCopter/Copter.h
+++ b/ArduCopter/Copter.h
@@ -545,7 +545,7 @@ private:
     AP_ADSB adsb;
 
     // avoidance of adsb enabled vehicles (normally manned vehicles)
-    AP_Avoidance_Copter avoidance_adsb{ahrs, adsb};
+    AP_Avoidance_Copter avoidance_adsb{adsb};
 #endif
 
     // last valid RC input time
diff --git a/ArduCopter/avoidance_adsb.cpp b/ArduCopter/avoidance_adsb.cpp
index 7eaffe81be..6e90d79d77 100644
--- a/ArduCopter/avoidance_adsb.cpp
+++ b/ArduCopter/avoidance_adsb.cpp
@@ -169,7 +169,7 @@ bool AP_Avoidance_Copter::handle_avoidance_vertical(const AP_Avoidance::Obstacle
     // decide on whether we should climb or descend
     bool should_climb = false;
     Location my_loc;
-    if (_ahrs.get_position(my_loc)) {
+    if (AP::ahrs().get_position(my_loc)) {
         should_climb = my_loc.alt > obstacle->_location.alt;
     }
 
diff --git a/ArduCopter/avoidance_adsb.h b/ArduCopter/avoidance_adsb.h
index 0ca023f241..d646d1303a 100644
--- a/ArduCopter/avoidance_adsb.h
+++ b/ArduCopter/avoidance_adsb.h
@@ -8,10 +8,8 @@
 // functionality - for example, not doing anything while landed.
 class AP_Avoidance_Copter : public AP_Avoidance {
 public:
-    AP_Avoidance_Copter(AP_AHRS &ahrs, class AP_ADSB &adsb)
-        : AP_Avoidance(ahrs, adsb)
-    {
-    }
+
+    using AP_Avoidance::AP_Avoidance;
 
     /* Do not allow copies */
     AP_Avoidance_Copter(const AP_Avoidance_Copter &other) = delete;