diff --git a/Assets/NewtonVR/NVRAttachPointMapper.cs b/Assets/NewtonVR/NVRAttachPointMapper.cs
index 30d5f206..3a32387d 100644
--- a/Assets/NewtonVR/NVRAttachPointMapper.cs
+++ b/Assets/NewtonVR/NVRAttachPointMapper.cs
@@ -13,12 +13,12 @@ public class AttachPointMapper
 
         public static void Register(Collider col, NVRAttachPoint point)
         {
-            Colliders.Add(col, point);
+            if (!Colliders.ContainsKey(col) ) Colliders.Add(col, point);
         }
 
         public static void Deregister(Collider col)
         {
-            Colliders.Remove(col);
+            if (Colliders.ContainsKey(col)) Colliders.Remove(col);
         }
 
         public static NVRAttachPoint GetAttachPoint(Collider col)
@@ -30,4 +30,4 @@ public static NVRAttachPoint GetAttachPoint(Collider col)
             return point;
         }
     }
-}
\ No newline at end of file
+}