diff --git a/Runtime/Scripts/Core/Cluster.cs b/Runtime/Scripts/Core/Cluster.cs
index b105e5b..ef0cac0 100644
--- a/Runtime/Scripts/Core/Cluster.cs
+++ b/Runtime/Scripts/Core/Cluster.cs
@@ -66,6 +66,7 @@ namespace NanoBrain {
         /// </summary>
         /// In a multi-cluster each instance can be used for a thing.
         /// Cluster instance may also not (yet) be mapped to a thing.
+        [NonSerialized]
         public Dictionary<int, Cluster> thingClusters = new();
 
         /// <summary>