diff --git a/libraries/AP_Proximity/AP_Proximity_SITL.cpp b/libraries/AP_Proximity/AP_Proximity_SITL.cpp
index 201d09a462..feec22c898 100644
--- a/libraries/AP_Proximity/AP_Proximity_SITL.cpp
+++ b/libraries/AP_Proximity/AP_Proximity_SITL.cpp
@@ -52,20 +52,19 @@ void AP_Proximity_SITL::update(void)
         // only called to prompt polyfence to reload fence if required
     }
     if (AP::fence()->polyfence().inclusion_boundary_available()) {
-        // update distance in one sector
-        boundary_location bnd_loc{last_sector};
-        boundary.reset_sector(bnd_loc);
-        float fence_distance;
-        if (get_distance_to_fence(boundary._sector_middle_deg[last_sector], fence_distance)) {
-            set_status(AP_Proximity::Status::Good);
-            boundary.set_attributes(bnd_loc, boundary._sector_middle_deg[last_sector], fence_distance);
-            boundary.update_boundary(bnd_loc);
-            // update OA database
-            database_push(boundary._sector_middle_deg[last_sector], fence_distance);
-        }
-        last_sector++;
-        if (last_sector >= PROXIMITY_NUM_SECTORS) {
-            last_sector = 0;
+        // update distance in each sector
+        for (uint8_t sector=0; sector < PROXIMITY_NUM_SECTORS; sector++) {
+            const float yaw_angle_deg = sector * 45.0f;
+            AP_Proximity_Boundary_3D::Face face = boundary.get_face(yaw_angle_deg);
+            float fence_distance;
+            if (get_distance_to_fence(yaw_angle_deg, fence_distance)) {
+                set_status(AP_Proximity::Status::Good);
+                boundary.set_face_attributes(face, yaw_angle_deg, fence_distance);
+                // update OA database
+                database_push(yaw_angle_deg, fence_distance);
+            } else {
+                boundary.reset_face(face);
+            }
         }
     } else {
         set_status(AP_Proximity::Status::NoData);