Index: source/network/NetClient.h
===================================================================
--- source/network/NetClient.h
+++ source/network/NetClient.h
@@ -159,7 +159,7 @@
 	 * Get the script interface associated with this network client,
 	 * which is equivalent to the one used by the CGame in the constructor.
 	 */
-	ScriptInterface& GetScriptInterface();
+	const ScriptInterface& GetScriptInterface();
 
 	/**
 	 * Send a message to the server.
@@ -189,7 +189,7 @@
 	 */
 	void LoadFinished();
 
-	void SendGameSetupMessage(JS::MutableHandleValue attrs, ScriptInterface& scriptInterface);
+	void SendGameSetupMessage(JS::MutableHandleValue attrs, const ScriptInterface& scriptInterface);
 
 	void SendAssignPlayerMessage(const int playerID, const CStr& guid);
 
Index: source/network/NetClient.cpp
===================================================================
--- source/network/NetClient.cpp
+++ source/network/NetClient.cpp
@@ -269,7 +269,7 @@
 	return r;
 }
 
-ScriptInterface& CNetClient::GetScriptInterface()
+const ScriptInterface& CNetClient::GetScriptInterface()
 {
 	return m_Game->GetSimulation2()->GetScriptInterface();
 }
@@ -328,7 +328,7 @@
 	SetCurrState(NCS_UNCONNECTED);
 }
 
-void CNetClient::SendGameSetupMessage(JS::MutableHandleValue attrs, ScriptInterface& scriptInterface)
+void CNetClient::SendGameSetupMessage(JS::MutableHandleValue attrs, const ScriptInterface& scriptInterface)
 {
 	CGameSetupMessage gameSetup(scriptInterface);
 	gameSetup.m_Data = attrs;
Index: source/network/NetClientTurnManager.cpp
===================================================================
--- source/network/NetClientTurnManager.cpp
+++ source/network/NetClientTurnManager.cpp
@@ -135,7 +135,7 @@
 
 	LOGERROR("Out-Of-Sync on turn %d\nPlayers: %s\nDumping state to %s", turn, playerNamesString.str().c_str(), oosdumpPath.string8());
 
-	ScriptInterface& scriptInterface = m_NetClient.GetScriptInterface();
+	const ScriptInterface& scriptInterface = m_NetClient.GetScriptInterface();
 	JSContext* cx = scriptInterface.GetContext();
 	JSAutoRequest rq(cx);
 
Index: source/network/NetServer.h
===================================================================
--- source/network/NetServer.h
+++ source/network/NetServer.h
@@ -126,7 +126,7 @@
 	 * The changes will be asynchronously propagated to all clients.
 	 * @param attrs game attributes, in the script context of scriptInterface
 	 */
-	void UpdateGameAttributes(JS::MutableHandleValue attrs, ScriptInterface& scriptInterface);
+	void UpdateGameAttributes(JS::MutableHandleValue attrs, const ScriptInterface& scriptInterface);
 
 	/**
 	 * Set the turn length to a fixed value.
@@ -221,7 +221,7 @@
 	/**
 	 * Get the script context used for game attributes.
 	 */
-	ScriptInterface& GetScriptInterface();
+	const ScriptInterface& GetScriptInterface();
 
 	/**
 	 * Set the turn length to a fixed value.
Index: source/network/NetServer.cpp
===================================================================
--- source/network/NetServer.cpp
+++ source/network/NetServer.cpp
@@ -845,7 +845,7 @@
 	Broadcast(&message, { NSS_PREGAME, NSS_JOIN_SYNCING, NSS_INGAME });
 }
 
-ScriptInterface& CNetServerWorker::GetScriptInterface()
+const ScriptInterface& CNetServerWorker::GetScriptInterface()
 {
 	return *m_ScriptInterface;
 }
@@ -1068,7 +1068,7 @@
 		// Ignore messages sent by one player on behalf of another player
 		// unless cheating is enabled
 		bool cheatsEnabled = false;
-		ScriptInterface& scriptInterface = server.GetScriptInterface();
+		const ScriptInterface& scriptInterface = server.GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 		JS::RootedValue settings(cx);
@@ -1502,7 +1502,7 @@
 	m_Worker->m_StartGameQueue.push_back(true);
 }
 
-void CNetServer::UpdateGameAttributes(JS::MutableHandleValue attrs, ScriptInterface& scriptInterface)
+void CNetServer::UpdateGameAttributes(JS::MutableHandleValue attrs, const ScriptInterface& scriptInterface)
 {
 	// Pass the attributes as JSON, since that's the easiest safe
 	// cross-thread way of passing script data
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
@@ -19,7 +19,6 @@
 #define INCLUDED_TEMPLATELOADER
 
 #include "simulation2/system/ParamNode.h"
-#include "scriptinterface/ScriptInterface.h"
 
 enum ETemplatesType
 {
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
@@ -359,7 +359,7 @@
 	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)
@@ -949,7 +949,7 @@
 
 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
@@ -1045,7 +1045,7 @@
 
 	virtual void TryLoadSharedComponent()
 	{
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -1063,7 +1063,7 @@
 
 	virtual void RunGamestateInit()
 	{
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -1104,7 +1104,7 @@
 
 		ForceLoadEntityTemplates();
 
-		ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
+		const ScriptInterface& scriptInterface = GetSimContext().GetScriptInterface();
 		JSContext* cx = scriptInterface.GetContext();
 		JSAutoRequest rq(cx);
 
@@ -1169,7 +1169,7 @@
 		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/system/ComponentTest.h
===================================================================
--- source/simulation2/system/ComponentTest.h
+++ source/simulation2/system/ComponentTest.h
@@ -59,7 +59,7 @@
 		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);