diff --git a/libraries/AC_Fence/AC_Fence.cpp b/libraries/AC_Fence/AC_Fence.cpp
index 4ce2e3da3e..f0f66a99d1 100644
--- a/libraries/AC_Fence/AC_Fence.cpp
+++ b/libraries/AC_Fence/AC_Fence.cpp
@@ -73,9 +73,8 @@ const AP_Param::GroupInfo AC_Fence::var_info[] = {
 };
 
 /// Default constructor.
-AC_Fence::AC_Fence(const AP_AHRS& ahrs, const AP_InertialNav& inav) :
+AC_Fence::AC_Fence(const AP_AHRS_NavEKF& ahrs) :
     _ahrs(ahrs),
-    _inav(inav),
     _alt_max_backup(0),
     _circle_radius_backup(0),
     _alt_max_breach_distance(0),
@@ -132,7 +131,12 @@ bool AC_Fence::pre_arm_check(const char* &fail_msg) const
     }
 
     // if we have horizontal limits enabled, check inertial nav position is ok
-    if ((_enabled_fences & (AC_FENCE_TYPE_CIRCLE | AC_FENCE_TYPE_POLYGON))>0 && !_inav.get_filter_status().flags.horiz_pos_abs && !_inav.get_filter_status().flags.pred_horiz_pos_abs) {
+    nav_filter_status filt_status;
+    if (!_ahrs.get_filter_status(filt_status)) {
+        fail_msg = "AHRS status not available";
+        return false;
+    }
+    if ((_enabled_fences & (AC_FENCE_TYPE_CIRCLE | AC_FENCE_TYPE_POLYGON))>0 && !filt_status.flags.horiz_pos_abs && !filt_status.flags.pred_horiz_pos_abs) {
         fail_msg = "fence requires position";
         return false;
     }
@@ -232,18 +236,21 @@ uint8_t AC_Fence::check_fence(float curr_alt)
             load_polygon_from_eeprom();
         } else if (_boundary_valid) {
             // check if vehicle is outside the polygon fence
-            const Vector3f& position = _inav.get_position();
-            if (_poly_loader.boundary_breached(Vector2f(position.x, position.y), _boundary_num_points, _boundary, true)) {
-                // check if this is a new breach
-                if ((_breached_fences & AC_FENCE_TYPE_POLYGON) == 0) {
-                    // record that we have breached the polygon
-                    record_breach(AC_FENCE_TYPE_POLYGON);
-                    ret |= AC_FENCE_TYPE_POLYGON;
-                }
-            } else {
-                // clear breach if present
-                if ((_breached_fences & AC_FENCE_TYPE_POLYGON) != 0) {
-                    clear_breach(AC_FENCE_TYPE_POLYGON);
+            Vector2f position;
+            if (_ahrs.get_relative_position_NE_origin(position)) {  // don't check polyfence in case of bad position
+                position = position * 100.0f;  // m to cm
+                if (_poly_loader.boundary_breached(position, _boundary_num_points, _boundary, true)) {
+                    // check if this is a new breach
+                    if ((_breached_fences & AC_FENCE_TYPE_POLYGON) == 0) {
+                        // record that we have breached the polygon
+                        record_breach(AC_FENCE_TYPE_POLYGON);
+                        ret |= AC_FENCE_TYPE_POLYGON;
+                    }
+                } else {
+                    // clear breach if present
+                    if ((_breached_fences & AC_FENCE_TYPE_POLYGON) != 0) {
+                        clear_breach(AC_FENCE_TYPE_POLYGON);
+                    }
                 }
             }
         }
@@ -276,11 +283,10 @@ bool AC_Fence::check_destination_within_fence(const Location_Class& loc)
     // polygon fence check
     if ((get_enabled_fences() & AC_FENCE_TYPE_POLYGON) && _boundary_num_points > 0) {
         // check ekf has a good location
-        Location temp_loc;
-        if (_inav.get_location(temp_loc)) {
-            const struct Location &ekf_origin = _inav.get_origin();
-            Vector2f position = location_diff(ekf_origin, loc) * 100.0f;
-            if (_poly_loader.boundary_breached(position, _boundary_num_points, _boundary, true)) {
+        Vector2f posNE;
+        if (_ahrs.get_relative_position_NE_origin(posNE)) {
+            posNE = posNE * 100.0f;  // m to cm
+            if (_poly_loader.boundary_breached(posNE, _boundary_num_points, _boundary, true)) {
                 return false;
             }
         }
@@ -432,10 +438,11 @@ bool AC_Fence::load_polygon_from_eeprom(bool force_reload)
 
     // get current location from EKF
     Location temp_loc;
-    if (!_inav.get_location(temp_loc)) {
+    if (!_ahrs.get_location(temp_loc)) {
         return false;
     }
-    const struct Location &ekf_origin = _inav.get_origin();
+    struct Location ekf_origin {};
+    _ahrs.get_origin(ekf_origin);
 
     // sanity check total
     _total = constrain_int16(_total, 0, _poly_loader.max_points());
diff --git a/libraries/AC_Fence/AC_Fence.h b/libraries/AC_Fence/AC_Fence.h
index 06bee2ee59..696ee4c347 100644
--- a/libraries/AC_Fence/AC_Fence.h
+++ b/libraries/AC_Fence/AC_Fence.h
@@ -6,7 +6,6 @@
 #include <AP_Math/AP_Math.h>
 #include <GCS_MAVLink/GCS_MAVLink.h>
 #include <AP_AHRS/AP_AHRS.h>
-#include <AP_InertialNav/AP_InertialNav.h>     // Inertial Navigation library
 #include <AC_Fence/AC_PolyFence_loader.h>
 #include <AP_Common/Location.h>
 
@@ -35,8 +34,8 @@
 class AC_Fence
 {
 public:
-    static AC_Fence create(const AP_AHRS &ahrs, const AP_InertialNav &inav) {
-        return AC_Fence{ahrs, inav};
+    static AC_Fence create(const AP_AHRS_NavEKF &ahrs) {
+        return AC_Fence{ahrs};
     }
 
     constexpr AC_Fence(AC_Fence &&other) = default;
@@ -123,7 +122,7 @@ public:
     static const struct AP_Param::GroupInfo var_info[];
 
 private:
-    AC_Fence(const AP_AHRS &ahrs, const AP_InertialNav &inav);
+    AC_Fence(const AP_AHRS_NavEKF &ahrs);
 
     /// record_breach - update breach bitmask, time and count
     void record_breach(uint8_t fence_type);
@@ -135,8 +134,7 @@ private:
     bool load_polygon_from_eeprom(bool force_reload = false);
 
     // pointers to other objects we depend upon
-    const AP_AHRS& _ahrs;
-    const AP_InertialNav& _inav;
+    const AP_AHRS_NavEKF& _ahrs;
 
     // parameters
     AP_Int8         _enabled;               // top level enable/disable control