Index: source/gui/ObjectBases/IGUIObject.cpp
===================================================================
--- source/gui/ObjectBases/IGUIObject.cpp
+++ source/gui/ObjectBases/IGUIObject.cpp
@@ -453,16 +453,12 @@
 {
 	ScriptRequest rq(m_pGUI.GetScriptInterface());
 
-	// TODO SM60: actually use this when we can use GetProxyPrivate
 	JS::RootedValue priv(rq.cx);
-	//priv.get().setPrivate(this); -> need to use a virtual func.
+	priv.get().setPrivate(this);
 
 	js::ProxyOptions options;
 	options.setClass(&JSI_GUIProxy<IGUIObject>::ClassDefinition());
 	m_JSObject.init(rq.cx, js::NewProxyObject(rq.cx, &JSI_GUIProxy<IGUIObject>::Singleton(), priv, nullptr, options));
-
-	// TODO: remove this when we can use GetProxyPrivate
-	JS_SetPrivate(m_JSObject.get(), this);
 }
 
 JSObject* IGUIObject::GetJSObject()
Index: source/gui/ObjectTypes/CText.cpp
===================================================================
--- source/gui/ObjectTypes/CText.cpp
+++ source/gui/ObjectTypes/CText.cpp
@@ -258,16 +258,12 @@
 {
 	ScriptRequest rq(m_pGUI.GetScriptInterface());
 
-	// TODO SM60: actually use this when we can use GetProxyPrivate
 	JS::RootedValue priv(rq.cx);
-	//priv.get().setPrivate(this); -> need to use a virtual func.
+	priv.get().setPrivate(this);
 
 	js::ProxyOptions options;
 	options.setClass(&JSI_GUIProxy<IGUIObject>::ClassDefinition());
 	m_JSObject.init(rq.cx, js::NewProxyObject(rq.cx, &JSI_GUIProxy<CText>::Singleton(), priv, nullptr, options));
-
-	// TODO: remove this when we can use GetProxyPrivate
-	JS_SetPrivate(m_JSObject.get(), this);
 }
 
 bool CText::getTextSize(ScriptInterface& scriptInterface, JS::MutableHandleValue ret)
Index: source/gui/Scripting/JSInterface_GUIProxy.h
===================================================================
--- source/gui/Scripting/JSInterface_GUIProxy.h
+++ source/gui/Scripting/JSInterface_GUIProxy.h
@@ -84,9 +84,9 @@
 		return true;
 	}
 	// Return nothing.
-	virtual bool enumerate(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), JS::MutableHandleObject UNUSED(objp)) const override
+	virtual JSObject* enumerate(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy)) const override
 	{
-		return true;
+		return nullptr;
 	}
 	// Throw an exception is JS attempts to query the prototype.
 	virtual bool getPrototypeIfOrdinary(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), bool* UNUSED(isOrdinary), JS::MutableHandleObject UNUSED(protop)) const override
Index: source/gui/Scripting/JSInterface_GUIProxy_impl.h
===================================================================
--- source/gui/Scripting/JSInterface_GUIProxy_impl.h
+++ source/gui/Scripting/JSInterface_GUIProxy_impl.h
@@ -20,7 +20,7 @@
 template <typename T>
 js::Class& JSI_GUIProxy<T>::ClassDefinition()
 {
-	static js::Class c = PROXY_CLASS_DEF("GUIObjectProxy", JSCLASS_HAS_PRIVATE | JSCLASS_HAS_CACHED_PROTO(JSProto_Proxy));
+	static js::Class c = PROXY_CLASS_DEF("GUIObjectProxy", JSCLASS_HAS_PRIVATE | JSCLASS_HAS_CACHED_PROTO(JSProto_Proxy) | JSCLASS_HAS_RESERVED_SLOTS(1));
 	return c;
 }
 
@@ -37,7 +37,7 @@
 inline bool apply_to(JSContext* cx, uint argc, JS::Value* vp)
 {
 	JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
-	OG* e = static_cast<OG*>(JS_GetPrivate(args.thisv().toObjectOrNull()));
+	OG* e = static_cast<OG*>(js::GetProxyPrivate(args.thisv().toObjectOrNull()).toPrivate());
 	if (!e)
 		return false;
 
Index: source/gui/Scripting/JSInterface_GUISize.cpp
===================================================================
--- source/gui/Scripting/JSInterface_GUISize.cpp
+++ source/gui/Scripting/JSInterface_GUISize.cpp
@@ -30,7 +30,7 @@
 	nullptr, nullptr,
 	nullptr, nullptr,
 	nullptr, nullptr, nullptr, nullptr,
-	nullptr, nullptr, JSI_GUISize::construct, nullptr
+	nullptr, JSI_GUISize::construct, nullptr
 };
 
 JSFunctionSpec JSI_GUISize::JSI_methods[] =
Index: source/scriptinterface/ScriptContext.cpp
===================================================================
--- source/scriptinterface/ScriptContext.cpp
+++ source/scriptinterface/ScriptContext.cpp
@@ -219,7 +219,7 @@
 					printf("Finishing incremental GC because gcBytes > m_ContextSize / 2. \n");
 #endif
 					PrepareCompartmentsForIncrementalGC();
-					JS::FinishIncrementalGC(m_cx, JS::gcreason::REFRESH_FRAME);
+					JS::FinishIncrementalGC(m_cx, JS::gcreason::API);
 				}
 				else
 				{
@@ -249,9 +249,9 @@
 #endif
 				PrepareCompartmentsForIncrementalGC();
 				if (!JS::IsIncrementalGCInProgress(m_cx))
-					JS::StartIncrementalGC(m_cx, GC_NORMAL, JS::gcreason::REFRESH_FRAME, GCSliceTimeBudget);
+					JS::StartIncrementalGC(m_cx, GC_NORMAL, JS::gcreason::API, GCSliceTimeBudget);
 				else
-					JS::IncrementalGCSlice(m_cx, JS::gcreason::REFRESH_FRAME, GCSliceTimeBudget);
+					JS::IncrementalGCSlice(m_cx, JS::gcreason::API, GCSliceTimeBudget);
 			}
 			m_LastGCBytes = gcBytes;
 		}
@@ -262,7 +262,7 @@
 {
 	JS_SetGCParameter(m_cx, JSGC_MODE, JSGC_MODE_ZONE);
 	JS::PrepareForFullGC(m_cx);
-	JS::GCForReason(m_cx, GC_SHRINK, JS::gcreason::REFRESH_FRAME);
+	JS::GCForReason(m_cx, GC_SHRINK, JS::gcreason::API);
 	JS_SetGCParameter(m_cx, JSGC_MODE, JSGC_MODE_INCREMENTAL);
 }
 
Index: source/scriptinterface/ScriptInterface.cpp
===================================================================
--- source/scriptinterface/ScriptInterface.cpp
+++ source/scriptinterface/ScriptInterface.cpp
@@ -98,7 +98,7 @@
 	nullptr, nullptr,
 	nullptr, nullptr,
 	nullptr, nullptr, nullptr,
-	nullptr, nullptr, nullptr, nullptr,
+	nullptr, nullptr, nullptr,
 	JS_GlobalObjectTraceHook
 };
 
@@ -327,10 +327,7 @@
 	JS::CompartmentCreationOptions creationOpt;
 	// Keep JIT code during non-shrinking GCs. This brings a quite big performance improvement.
 	creationOpt.setPreserveJitCode(true);
-	JS::CompartmentBehaviors behaviors;
-	behaviors.setVersion(JSVERSION_LATEST);
-
-	JS::CompartmentOptions opt(creationOpt, behaviors);
+	JS::CompartmentOptions opt(creationOpt, JS::CompartmentBehaviors{});
 
 	JSAutoRequest rq(m_cx);
 	m_glob = JS_NewGlobalObject(m_cx, &global_class, nullptr, JS::OnNewGlobalHookOption::FireOnNewGlobalHook, opt);
@@ -494,7 +491,7 @@
 	                                           ps, fs,                   // Properties, methods
 	                                           static_ps, static_fs));   // Constructor properties, methods
 
-	if (obj == NULL)
+	if (obj == nullptr)
 	{
 		ScriptException::CatchPending(rq);
 		throw PSERROR_Scripting_DefineType_CreationFailed();
Index: source/simulation2/serialization/BinarySerializer.cpp
===================================================================
--- source/simulation2/serialization/BinarySerializer.cpp
+++ source/simulation2/serialization/BinarySerializer.cpp
@@ -68,7 +68,7 @@
 
 	switch (JS_TypeOfValue(rq.cx, val))
 	{
-	case JSTYPE_VOID:
+	case JSTYPE_UNDEFINED:
 	{
 		m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_VOID);
 		break;