Index: source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Object/Object.h
===================================================================
--- source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Object/Object.h
+++ source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Object/Object.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2022 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -26,6 +26,7 @@
 	ObjectSidebar(ScenarioEditor& scenarioEditor, wxWindow* sidebarContainer, wxWindow* bottomBarContainer);
 	~ObjectSidebar();
 	void FilterObjects();
+	bool Show(bool show) override;
 
 protected:
 	virtual void OnFirstDisplay();
Index: source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Object/Object.cpp
===================================================================
--- source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Object/Object.cpp
+++ source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Object/Object.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2022 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -300,6 +300,16 @@
 	delete m_Impl;
 }
 
+//Intercept on hide to close the actorviewer
+bool ObjectSidebar::Show(bool show)
+{
+	if (!show)
+	{
+		m_ScenarioEditor.GetToolManager().SetCurrentTool(_T(""), NULL);
+	}
+	return Sidebar::Show(show);
+}
+
 void ObjectSidebar::OnToolChange(ITool* tool)
 {
 	if (wxString(tool->GetClassInfo()->GetClassName()) == _T("ActorViewerTool"))