Index: source/ps/Game.cpp
===================================================================
--- source/ps/Game.cpp
+++ source/ps/Game.cpp
@@ -173,7 +173,6 @@
 	debug_printf("Starting to replay %s\n", replayPath.string8().c_str());
 
 	m_IsVisualReplay = true;
-	ScriptInterface& scriptInterface = m_Simulation2->GetScriptInterface();
 
 	SetTurnManager(new CReplayTurnManager(*m_Simulation2, GetReplayLogger()));
 
@@ -186,6 +185,7 @@
 	std::string line;
 	std::getline(*m_ReplayStream, line);
 
+	const ScriptInterface& scriptInterface = m_Simulation2->GetScriptInterface();
 	JSContext* cx = scriptInterface.GetContext();
 	JSAutoRequest rq(cx);
 
@@ -203,7 +203,7 @@
  **/
 void CGame::RegisterInit(const JS::HandleValue attribs, const std::string& savedState)
 {
-	ScriptInterface& scriptInterface = m_Simulation2->GetScriptInterface();
+	const ScriptInterface& scriptInterface = m_Simulation2->GetScriptInterface();
 	JSContext* cx = scriptInterface.GetContext();
 	JSAutoRequest rq(cx);
 
Index: source/ps/TemplateLoader.h
===================================================================
--- source/ps/TemplateLoader.h
+++ source/ps/TemplateLoader.h
@@ -65,7 +65,7 @@
 	 */
 	std::vector<std::string> FindTemplates(const std::string& path, bool includeSubdirectories, ETemplatesType templatesType) const;
 
-	std::vector<std::string> FindPlaceableTemplates(const std::string& path, bool includeSubdirectories, ETemplatesType templatesType, ScriptInterface& scriptInterface) const;
+	std::vector<std::string> FindPlaceableTemplates(const std::string& path, bool includeSubdirectories, ETemplatesType templatesType, const ScriptInterface& scriptInterface) const;
 
 private:
 	/**
Index: source/ps/TemplateLoader.cpp
===================================================================
--- source/ps/TemplateLoader.cpp
+++ source/ps/TemplateLoader.cpp
@@ -152,7 +152,7 @@
 	return VfsFileExists(VfsPath(TEMPLATE_ROOT) / wstring_from_utf8(baseName + ".xml"));
 }
 
-std::vector<std::string> CTemplateLoader::FindPlaceableTemplates(const std::string& path, bool includeSubdirectories, ETemplatesType templatesType, ScriptInterface& scriptInterface) const
+std::vector<std::string> CTemplateLoader::FindPlaceableTemplates(const std::string& path, bool includeSubdirectories, ETemplatesType templatesType, const ScriptInterface& scriptInterface) const
 {
 	if (templatesType != SIMULATION_TEMPLATES && templatesType != ACTOR_TEMPLATES && templatesType != ALL_TEMPLATES)
 	{
Index: source/scriptinterface/ScriptInterface.h
===================================================================
--- source/scriptinterface/ScriptInterface.h
+++ source/scriptinterface/ScriptInterface.h
@@ -134,9 +134,7 @@
 	JSObject* CreateCustomObject(const std::string & typeName) const;
 	void DefineCustomObjectType(JSClass *clasp, JSNative constructor, uint minArgs, JSPropertySpec *ps, JSFunctionSpec *fs, JSPropertySpec *static_ps, JSFunctionSpec *static_fs);
 
-	JS::Value GetGlobalObject();
-
-	JSClass* GetGlobalClass();
+	JS::Value GetGlobalObject() const;
 
 	/**
 	 * Set the named property on the global object.
Index: source/scriptinterface/ScriptInterface.cpp
===================================================================
--- source/scriptinterface/ScriptInterface.cpp
+++ source/scriptinterface/ScriptInterface.cpp
@@ -596,17 +596,12 @@
 	return ok;
 }
 
-JS::Value ScriptInterface::GetGlobalObject()
+JS::Value ScriptInterface::GetGlobalObject() const
 {
 	JSAutoRequest rq(m->m_cx);
 	return JS::ObjectValue(*JS::CurrentGlobalOrNull(m->m_cx));
 }
 
-JSClass* ScriptInterface::GetGlobalClass()
-{
-	return &global_class;
-}
-
 bool ScriptInterface::SetGlobal_(const char* name, JS::HandleValue value, bool replace)
 {
 	JSAutoRequest rq(m->m_cx);
Index: source/simulation2/Simulation2.cpp
===================================================================
--- source/simulation2/Simulation2.cpp
+++ source/simulation2/Simulation2.cpp
@@ -360,7 +360,7 @@
 	const bool serializationTestHash = true; // set true to save and compare hash of state
 
 	SerializationTestState primaryStateBefore;
-	ScriptInterface& scriptInterface = m_ComponentManager.GetScriptInterface();
+	const ScriptInterface& scriptInterface = m_ComponentManager.GetScriptInterface();
 
 	const bool startRejoinTest = (int64_t) m_RejoinTestTurn == m_TurnNumber;
 	if (startRejoinTest)
@@ -951,7 +951,7 @@
 
 std::string CSimulation2::GetAIData()
 {
-	ScriptInterface& scriptInterface = GetScriptInterface();
+	const ScriptInterface& scriptInterface = GetScriptInterface();
 	JSContext* cx = scriptInterface.GetContext();
 	JSAutoRequest rq(cx);
 	JS::RootedValue aiData(cx, ICmpAIManager::GetAIs(scriptInterface));
Index: source/simulation2/components/CCmpAIManager.cpp
===================================================================
--- source/simulation2/components/CCmpAIManager.cpp
+++ source/simulation2/components/CCmpAIManager.cpp
@@ -1044,7 +1044,7 @@
 
 	virtual void TryLoadSharedComponent()
 	{
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -1062,7 +1062,7 @@
 
 	virtual void RunGamestateInit()
 	{
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -1105,7 +1105,7 @@
 
 		ForceLoadEntityTemplates();
 
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -1170,7 +1170,7 @@
 		if (!cmpCommandQueue)
 			return;
 
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 		JS::RootedValue clonedCommandVal(cx);
@@ -1238,7 +1238,7 @@
 		if (!cmpPathfinder)
 			return;
 
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
Index: source/simulation2/components/CCmpCommandQueue.cpp
===================================================================
--- source/simulation2/components/CCmpCommandQueue.cpp
+++ source/simulation2/components/CCmpCommandQueue.cpp
@@ -105,7 +105,7 @@
 
 	virtual void FlushTurn(const std::vector<SimulationCommand>& commands)
 	{
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
Index: source/simulation2/components/CCmpTemplateManager.cpp
===================================================================
--- source/simulation2/components/CCmpTemplateManager.cpp
+++ source/simulation2/components/CCmpTemplateManager.cpp
@@ -218,7 +218,7 @@
 
 std::vector<std::string> CCmpTemplateManager::FindAllPlaceableTemplates(bool includeActors) const
 {
-	ScriptInterface& scriptInterface = this->GetSimContext().GetScriptInterface();
+	const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 
 	ETemplatesType templatesType = includeActors ? ALL_TEMPLATES : SIMULATION_TEMPLATES;
 	return m_templateLoader.FindPlaceableTemplates("", true, templatesType, scriptInterface);
Index: source/simulation2/system/ComponentTest.h
===================================================================
--- source/simulation2/system/ComponentTest.h
+++ source/simulation2/system/ComponentTest.h
@@ -58,7 +58,7 @@
 		m_ComponentManager.LoadComponentTypes();
 	}
 
-	ScriptInterface& GetScriptInterface()
+	const ScriptInterface& GetScriptInterface()
 	{
 		return m_ComponentManager.GetScriptInterface();
 	}
Index: source/tools/atlas/GameInterface/Handlers/MapHandlers.cpp
===================================================================
--- source/tools/atlas/GameInterface/Handlers/MapHandlers.cpp
+++ source/tools/atlas/GameInterface/Handlers/MapHandlers.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2016 Wildfire Games.
+/* Copyright (C) 2017 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -89,7 +89,7 @@
 		InitGame();
 
 		// Random map
-		ScriptInterface& scriptInterface = g_Game->GetSimulation2()->GetScriptInterface();
+		const ScriptInterface& scriptInterface = g_Game->GetSimulation2()->GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -116,7 +116,7 @@
 
 		InitGame();
 
-		ScriptInterface& scriptInterface = g_Game->GetSimulation2()->GetScriptInterface();
+		const ScriptInterface& scriptInterface = g_Game->GetSimulation2()->GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -149,7 +149,7 @@
 {
 	InitGame();
 
-	ScriptInterface& scriptInterface = g_Game->GetSimulation2()->GetScriptInterface();
+	const ScriptInterface& scriptInterface = g_Game->GetSimulation2()->GetScriptInterface();
 	JSContext* cx = scriptInterface.GetContext();
 	JSAutoRequest rq(cx);