diff --git a/src/DynamoCore/Models/DynamoModel.cs b/src/DynamoCore/Models/DynamoModel.cs
index b7ec40cf93c..da453cf9cd0 100644
--- a/src/DynamoCore/Models/DynamoModel.cs
+++ b/src/DynamoCore/Models/DynamoModel.cs
@@ -492,6 +492,9 @@ protected virtual void ShutDownCore(bool shutdownHost)
             Dispose();
             PreferenceSettings.SaveInternal(pathManager.PreferenceFilePath);
 
+            //Remove reference on shutdown
+            PreferenceSettings.dynamoModelRuntimePreferenceSettings = null;
+
             OnCleanup();
 
             DynamoSelection.DestroyInstance();