diff --git a/Editor/ClusterEditor.cs b/Editor/ClusterEditor.cs
index 1498a79..44ac86f 100644
--- a/Editor/ClusterEditor.cs
+++ b/Editor/ClusterEditor.cs
@@ -169,7 +169,7 @@ namespace NanoBrain {
                 GUILayout.Label(nucleusType, headerStyle);
 
                 // Nucleus name
-                if (this.currentNucleus.parent is Cluster parentCluster) {
+                if (this.currentNucleus is Cluster parentCluster) {
                     EditorGUILayout.BeginHorizontal();
                     if (GUILayout.Button(this.currentNucleus.parent.name))
                         OnClusterClick(parentCluster);