diff --git a/libraries/AP_AHRS/AP_AHRS.h b/libraries/AP_AHRS/AP_AHRS.h
index 2258fa4e0d..3eaa367c6b 100644
--- a/libraries/AP_AHRS/AP_AHRS.h
+++ b/libraries/AP_AHRS/AP_AHRS.h
@@ -485,6 +485,11 @@ private:
     AP_Float _custom_pitch;
     AP_Float _custom_yaw;
 
+    /*
+     * support for custom AHRS orientation, replacing _board_orientation
+     */
+    Matrix3f _custom_rotation;
+
     enum class EKFType {
         NONE = 0
 #if HAL_NAVEKF3_AVAILABLE
diff --git a/libraries/AP_AHRS/AP_AHRS_Backend.h b/libraries/AP_AHRS/AP_AHRS_Backend.h
index f95e484110..bfbeace493 100644
--- a/libraries/AP_AHRS/AP_AHRS_Backend.h
+++ b/libraries/AP_AHRS/AP_AHRS_Backend.h
@@ -430,8 +430,6 @@ protected:
     // multi-thread access support
     HAL_Semaphore _rsem;
 
-    Matrix3f _custom_rotation;
-
     // calculate sin/cos of roll/pitch/yaw from rotation
     void calc_trig(const Matrix3f &rot,
                    float &cr, float &cp, float &cy,