diff --git a/libraries/AP_Compass/AP_Compass_PX4.cpp b/libraries/AP_Compass/AP_Compass_PX4.cpp
index 44b69020ce..75c77905a3 100644
--- a/libraries/AP_Compass/AP_Compass_PX4.cpp
+++ b/libraries/AP_Compass/AP_Compass_PX4.cpp
@@ -69,8 +69,8 @@ bool AP_Compass_PX4::init(void)
         }
 
         // remember if the compass is external
-        _is_external[i] = (ioctl(_mag_fd[i], MAGIOCGEXTERNAL, 0) > 0);
-        if (_is_external[i]) {
+        _external[i] = (ioctl(_mag_fd[i], MAGIOCGEXTERNAL, 0) > 0);
+        if (_external[i]) {
             hal.console->printf("Using external compass[%u]\n", (unsigned)i);
         }
         _count[0] = 0;
@@ -108,12 +108,9 @@ bool AP_Compass_PX4::read(void)
         // a noop on most boards
         _sum[i].rotate(MAG_BOARD_ORIENTATION);
 
-        // override any user setting of COMPASS_EXTERNAL 
-        _external.set(_is_external[0]);
-
-        if (_is_external[i]) {
+        if (_external[i]) {
             // add user selectable orientation
-            _sum[i].rotate((enum Rotation)_orientation.get());
+            _sum[i].rotate((enum Rotation)_orientation[i].get());
         } else {
             // add in board orientation from AHRS
             _sum[i].rotate(_board_orientation);
diff --git a/libraries/AP_Compass/AP_Compass_PX4.h b/libraries/AP_Compass/AP_Compass_PX4.h
index 454ff80edc..a01602c132 100644
--- a/libraries/AP_Compass/AP_Compass_PX4.h
+++ b/libraries/AP_Compass/AP_Compass_PX4.h
@@ -28,7 +28,6 @@ private:
     Vector3f _sum[COMPASS_MAX_INSTANCES];
     uint32_t _count[COMPASS_MAX_INSTANCES];
     uint64_t _last_timestamp[COMPASS_MAX_INSTANCES];
-    bool _is_external[COMPASS_MAX_INSTANCES];
 };
 
 #endif // AP_Compass_PX4_H