diff --git a/Assets/External/OptiTrack Unity Plugin/OptiTrack/Scripts/OptitrackRigidBody.cs b/Assets/External/OptiTrack Unity Plugin/OptiTrack/Scripts/OptitrackRigidBody.cs
index 5221ebe1..1079519b 100644
--- a/Assets/External/OptiTrack Unity Plugin/OptiTrack/Scripts/OptitrackRigidBody.cs	
+++ b/Assets/External/OptiTrack Unity Plugin/OptiTrack/Scripts/OptitrackRigidBody.cs	
@@ -15,12 +15,14 @@ limitations under the License.
 */
 
 using System;
+using KindRetargeting;
 using UnityEngine;
 
 
 /// <summary>
 /// Implements live tracking of streamed OptiTrack rigid body data onto an object.
 /// </summary>
+[RequireComponent(typeof(PropTypeController))]
 public class OptitrackRigidBody : MonoBehaviour
 {
     [Tooltip("The ID of the rigid body to track.")]