diff --git a/Assets/Fungus/Flowchart/Scripts/Commands/SetActive.cs b/Assets/Fungus/Flowchart/Scripts/Commands/SetActive.cs
index 69ad01b7..9116185a 100644
--- a/Assets/Fungus/Flowchart/Scripts/Commands/SetActive.cs
+++ b/Assets/Fungus/Flowchart/Scripts/Commands/SetActive.cs
@@ -1,4 +1,5 @@
 using UnityEngine;
+using UnityEngine.Serialization;
 using System.Collections;
 using System.Collections.Generic;
 
@@ -8,19 +9,23 @@ namespace Fungus
 	             "Set Active", 
 	             "Sets a game object in the scene to be active / inactive.")]
 	[AddComponentMenu("")]
-	public class SetActive : Command
-	{	
+	public class SetActive : Command, ISerializationCallbackReceiver
+	{
+		#region Obsolete Properties
+		[HideInInspector] [FormerlySerializedAs("targetGameObject")] public GameObject targetGameObjectOLD;
+		#endregion
+
 		[Tooltip("Reference to game object to enable / disable")]
-		public GameObject targetGameObject;
+		public GameObjectData _targetGameObject;
 
 		[Tooltip("Set to true to enable the game object")]
 		public BooleanData activeState;
 	
 		public override void OnEnter()
 		{
-			if (targetGameObject != null)
+			if (_targetGameObject.Value != null)
 			{
-				targetGameObject.SetActive(activeState.Value);
+				_targetGameObject.Value.SetActive(activeState.Value);
 			}
 
 			Continue();
@@ -28,18 +33,34 @@ namespace Fungus
 
 		public override string GetSummary()
 		{
-			if (targetGameObject == null)
+			if (_targetGameObject.Value == null)
 			{
 				return "Error: No game object selected";
 			}
 
-			return targetGameObject.name + " = " + activeState.GetDescription();
+			return _targetGameObject.Value.name + " = " + activeState.GetDescription();
 		}
 
 		public override Color GetButtonColor()
 		{
 			return new Color32(235, 191, 217, 255);
 		}
+
+		//
+		// ISerializationCallbackReceiver implementation
+		//
+
+		public virtual void OnBeforeSerialize()
+		{}
+
+		public virtual void OnAfterDeserialize()
+		{
+			if (targetGameObjectOLD != null)
+			{
+				_targetGameObject.Value = targetGameObjectOLD;
+				targetGameObjectOLD = null;
+			}
+		}
 	}
 
 }
\ No newline at end of file
diff --git a/Assets/UpdatePropTest.unity b/Assets/UpdatePropTest.unity
index 70052c24..19c7b431 100644
--- a/Assets/UpdatePropTest.unity
+++ b/Assets/UpdatePropTest.unity
@@ -306,6 +306,9 @@ GameObject:
   - 114: {fileID: 979963250}
   - 114: {fileID: 979963251}
   - 114: {fileID: 979963252}
+  - 114: {fileID: 979963255}
+  - 114: {fileID: 979963254}
+  - 114: {fileID: 979963253}
   m_Layer: 0
   m_Name: Flowchart
   m_TagString: Untagged
@@ -339,7 +342,7 @@ MonoBehaviour:
     height: 859
   selectedBlock: {fileID: 979963241}
   selectedCommands:
-  - {fileID: 979963250}
+  - {fileID: 979963253}
   variables:
   - {fileID: 979963244}
   - {fileID: 979963252}
@@ -405,7 +408,10 @@ MonoBehaviour:
   - {fileID: 979963249}
   - {fileID: 979963248}
   - {fileID: 979963250}
+  - {fileID: 979963255}
   - {fileID: 979963251}
+  - {fileID: 979963254}
+  - {fileID: 979963253}
 --- !u!114 &979963242
 MonoBehaviour:
   m_ObjectHideFlags: 2
@@ -607,7 +613,66 @@ MonoBehaviour:
   m_EditorClassIdentifier: 
   scope: 0
   key: Var1
-  value: {fileID: 0}
+  value: {fileID: 1766204518}
+--- !u!114 &979963253
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_PrefabParentObject: {fileID: 0}
+  m_PrefabInternal: {fileID: 0}
+  m_GameObject: {fileID: 979963238}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: dbd8c931f22994b9d90e2037fffaa770, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  itemId: 11
+  errorMessage: 
+  indentLevel: 0
+  targetGameObjectOLD: {fileID: 0}
+  _targetGameObject:
+    gameObjectRef: {fileID: 0}
+    gameObjectVal: {fileID: 837453083}
+  activeState:
+    booleanRef: {fileID: 0}
+    booleanVal: 0
+--- !u!114 &979963254
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_PrefabParentObject: {fileID: 0}
+  m_PrefabInternal: {fileID: 0}
+  m_GameObject: {fileID: 979963238}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: c43743931d28f43f89eced820d907351, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  itemId: 10
+  errorMessage: 
+  indentLevel: 0
+  messageOLD: 
+  messageTarget: 0
+  _message:
+    stringRef: {fileID: 0}
+    stringVal: 
+--- !u!114 &979963255
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_PrefabParentObject: {fileID: 0}
+  m_PrefabInternal: {fileID: 0}
+  m_GameObject: {fileID: 979963238}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 00d03ae0919f04264b018681ed534177, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  itemId: 9
+  errorMessage: 
+  indentLevel: 0
+  sceneNameOLD: 
+  _sceneName:
+    stringRef: {fileID: 0}
+    stringVal: 
+  loadingImage: {fileID: 0}
 --- !u!1 &1197120973
 GameObject:
   m_ObjectHideFlags: 0