diff --git a/DDrawCompat/DDraw/DirectDraw.cpp b/DDrawCompat/DDraw/DirectDraw.cpp
index 313cba2..abb3b1a 100644
--- a/DDrawCompat/DDraw/DirectDraw.cpp
+++ b/DDrawCompat/DDraw/DirectDraw.cpp
@@ -20,8 +20,6 @@
 
 namespace
 {
-	const DWORD SURFACE_LOST_FLAG = 0x10000000;
-
 	template <typename TDirectDraw, typename TSurfaceDesc, typename TSurface>
 	HRESULT STDMETHODCALLTYPE CreateSurface(
 		TDirectDraw* This, TSurfaceDesc* lpDDSurfaceDesc, TSurface** lplpDDSurface, IUnknown* pUnkOuter)
@@ -110,12 +108,12 @@ namespace
 	HRESULT WINAPI restoreSurfaceLostFlag(
 		LPDIRECTDRAWSURFACE7 lpDDSurface, LPDDSURFACEDESC2 /*lpDDSurfaceDesc*/, LPVOID lpContext)
 	{
-		auto& surfacesToRestore = *static_cast<std::set<void*>*>(lpContext);
-		auto it = surfacesToRestore.find(DDraw::DirectDrawSurface::getSurfaceObject(*lpDDSurface));
+		auto& surfacesToRestore = *static_cast<std::set<DDRAWI_DDRAWSURFACE_LCL*>*>(lpContext);
+		auto lcl = DDraw::DirectDrawSurface::getInt(*lpDDSurface).lpLcl;
+		auto it = surfacesToRestore.find(lcl);
 		if (it != surfacesToRestore.end())
 		{
-			DWORD& flags = DDraw::DirectDrawSurface::getFlags(*lpDDSurface);
-			flags &= ~SURFACE_LOST_FLAG;
+			lcl->dwFlags &= ~DDRAWISURF_INVALID;
 			surfacesToRestore.erase(it);
 		}
 		return DDENUMRET_OK;
@@ -125,14 +123,14 @@ namespace
 		LPDIRECTDRAWSURFACE7 lpDDSurface, LPDDSURFACEDESC2 /*lpDDSurfaceDesc*/, LPVOID lpContext)
 	{
 		auto& surfacesToRestore = *static_cast<std::set<void*>*>(lpContext);
-		DWORD& flags = DDraw::DirectDrawSurface::getFlags(*lpDDSurface);
-		if (!(flags & SURFACE_LOST_FLAG))
+		auto lcl = DDraw::DirectDrawSurface::getInt(*lpDDSurface).lpLcl;
+		if (!(lcl->dwFlags & DDRAWISURF_INVALID))
 		{
 			auto resource = D3dDdi::Device::findResource(DDraw::DirectDrawSurface::getDriverResourceHandle(*lpDDSurface));
 			if (resource && !resource->getOrigDesc().Flags.MatchGdiPrimary)
 			{
-				flags |= SURFACE_LOST_FLAG;
-				surfacesToRestore.insert(DDraw::DirectDrawSurface::getSurfaceObject(*lpDDSurface));
+				lcl->dwFlags |= DDRAWISURF_INVALID;
+				surfacesToRestore.insert(lcl);
 			}
 		}
 		return DDENUMRET_OK;
@@ -212,7 +210,7 @@ namespace DDraw
 			}
 
 			DDraw::ScopedThreadLock lock;
-			std::set<void*> surfacesToRestore;
+			std::set<DDRAWI_DDRAWSURFACE_LCL*> surfacesToRestore;
 			TagSurface::forEachDirectDraw([&](CompatRef<IDirectDraw7> dd)
 				{
 					dd->EnumSurfaces(&dd, DDENUMSURFACES_DOESEXIST | DDENUMSURFACES_ALL, nullptr,
diff --git a/DDrawCompat/DDraw/DirectDraw.h b/DDrawCompat/DDraw/DirectDraw.h
index ebe8caf..16e1a45 100644
--- a/DDrawCompat/DDraw/DirectDraw.h
+++ b/DDrawCompat/DDraw/DirectDraw.h
@@ -3,6 +3,7 @@
 #include <functional>
 
 #include <ddraw.h>
+#include <ddrawi.h>
 
 #include <Common/CompatPtr.h>
 #include <Common/CompatRef.h>
@@ -18,15 +19,15 @@ namespace DDraw
 		void suppressEmulatedDirectDraw(GUID*& guid);
 
 		template <typename TDirectDraw>
-		void* getDdObject(TDirectDraw& dd)
+		DDRAWI_DIRECTDRAW_INT& getInt(TDirectDraw& dd)
 		{
-			return reinterpret_cast<void**>(&dd)[1];
+			return reinterpret_cast<DDRAWI_DIRECTDRAW_INT&>(dd);
 		}
 
 		template <typename TDirectDraw>
 		HWND* getDeviceWindowPtr(TDirectDraw& dd)
 		{
-			return &reinterpret_cast<HWND**>(&dd)[1][8];
+			return &reinterpret_cast<HWND>(getInt(dd).lpLcl->hWnd);
 		}
 
 		template <typename Vtable>
diff --git a/DDrawCompat/DDraw/DirectDrawSurface.h b/DDrawCompat/DDraw/DirectDrawSurface.h
index 7853934..4792994 100644
--- a/DDrawCompat/DDraw/DirectDrawSurface.h
+++ b/DDrawCompat/DDraw/DirectDrawSurface.h
@@ -3,6 +3,7 @@
 #include <vector>
 
 #include <Windows.h>
+#include <ddrawi.h>
 
 #include <Common/CompatPtr.h>
 #include <Common/CompatRef.h>
@@ -14,21 +15,15 @@ namespace DDraw
 		std::vector<CompatPtr<IDirectDrawSurface7>> getAllAttachedSurfaces(CompatRef<IDirectDrawSurface7> surface);
 
 		template <typename TSurface>
-		void* getSurfaceObject(TSurface& surface)
+		DDRAWI_DDRAWSURFACE_INT& getInt(TSurface& surface)
 		{
-			return reinterpret_cast<void**>(&surface)[1];
-		}
-
-		template <typename TSurface>
-		DWORD& getFlags(TSurface& surface)
-		{
-			return reinterpret_cast<DWORD**>(&surface)[1][7];
+			return reinterpret_cast<DDRAWI_DDRAWSURFACE_INT&>(surface);
 		}
 
 		template <typename TSurface>
 		HANDLE getRuntimeResourceHandle(TSurface& surface)
 		{
-			return reinterpret_cast<HANDLE**>(&surface)[1][2];
+			return reinterpret_cast<HANDLE>(getInt(surface).lpLcl->hDDSurface);
 		}
 
 		template <typename TSurface>
diff --git a/DDrawCompat/DDraw/Surfaces/TagSurface.cpp b/DDrawCompat/DDraw/Surfaces/TagSurface.cpp
index 6f4c2e7..74ea9db 100644
--- a/DDrawCompat/DDraw/Surfaces/TagSurface.cpp
+++ b/DDrawCompat/DDraw/Surfaces/TagSurface.cpp
@@ -6,14 +6,14 @@
 
 namespace
 {
-	std::map<void*, DDraw::TagSurface*> g_ddObjects;
+	std::map<DDRAWI_DIRECTDRAW_LCL*, DDraw::TagSurface*> g_ddObjects;
 }
 
 namespace DDraw
 {
-	TagSurface::TagSurface(DWORD origCaps, void* ddObject)
+	TagSurface::TagSurface(DWORD origCaps, DDRAWI_DIRECTDRAW_LCL* ddLcl)
 		: Surface(origCaps)
-		, m_ddObject(ddObject)
+		, m_ddLcl(ddLcl)
 		, m_fullscreenWindow(nullptr)
 		, m_fullscreenWindowStyle(0)
 		, m_fullscreenWindowExStyle(0)
@@ -23,7 +23,7 @@ namespace DDraw
 	TagSurface::~TagSurface()
 	{
 		setFullscreenWindow(nullptr);
-		g_ddObjects.erase(m_ddObject);
+		g_ddObjects.erase(m_ddLcl);
 	}
 
 	HRESULT TagSurface::create(CompatRef<IDirectDraw> dd)
@@ -35,9 +35,9 @@ namespace DDraw
 		desc.dwHeight = 1;
 		desc.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN | DDSCAPS_SYSTEMMEMORY;
 
-		auto ddObject = DDraw::DirectDraw::getDdObject(dd.get());
-		auto privateData(std::make_unique<TagSurface>(desc.ddsCaps.dwCaps, ddObject));
-		g_ddObjects[ddObject] = privateData.get();
+		auto ddLcl = DDraw::DirectDraw::getInt(dd.get()).lpLcl;
+		auto privateData(std::make_unique<TagSurface>(desc.ddsCaps.dwCaps, ddLcl));
+		g_ddObjects[ddLcl] = privateData.get();
 
 		IDirectDrawSurface* surface = nullptr;
 		return Surface::create(dd, desc, surface, std::move(privateData));
@@ -57,25 +57,20 @@ namespace DDraw
 
 	void TagSurface::forEachDirectDraw(std::function<void(CompatRef<IDirectDraw7>)> callback)
 	{
-		struct DirectDrawInterface
+		for (auto& ddObj : g_ddObjects)
 		{
-			const void* vtable;
-			void* ddObject;
-			DirectDrawInterface* next;
-			DWORD refCount;
-		};
-
-		for (auto ddObj : g_ddObjects)
-		{
-			DirectDrawInterface intf = { &CompatVtable<IDirectDraw7Vtbl>::s_origVtable, ddObj.first, nullptr, 1 };
+			DDRAWI_DIRECTDRAW_INT intf = {};
+			intf.lpVtbl = &CompatVtable<IDirectDraw7Vtbl>::s_origVtable;
+			intf.lpLcl = ddObj.first;
+			intf.dwIntRefCnt = 1;
 			callback(CompatRef<IDirectDraw7>(reinterpret_cast<IDirectDraw7&>(intf)));
 		}
 	}
 
 	TagSurface* TagSurface::get(CompatRef<IDirectDraw> dd)
 	{
-		auto ddObject = DDraw::DirectDraw::getDdObject(dd.get());
-		auto it = g_ddObjects.find(ddObject);
+		auto ddLcl = DDraw::DirectDraw::getInt(dd.get()).lpLcl;
+		auto it = g_ddObjects.find(ddLcl);
 		if (it != g_ddObjects.end())
 		{
 			return it->second;
@@ -85,7 +80,7 @@ namespace DDraw
 		{
 			return nullptr;
 		}
-		return g_ddObjects[ddObject];
+		return g_ddObjects[ddLcl];
 	}
 
 	void TagSurface::setFullscreenWindow(HWND hwnd)
diff --git a/DDrawCompat/DDraw/Surfaces/TagSurface.h b/DDrawCompat/DDraw/Surfaces/TagSurface.h
index bda76f2..d22e378 100644
--- a/DDrawCompat/DDraw/Surfaces/TagSurface.h
+++ b/DDrawCompat/DDraw/Surfaces/TagSurface.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <ddraw.h>
+#include <ddrawi.h>
 #include <functional>
 
 #include <Common/CompatRef.h>
@@ -11,7 +12,7 @@ namespace DDraw
 	class TagSurface : public Surface
 	{
 	public:
-		TagSurface(DWORD origCaps, void* ddObject);
+		TagSurface(DWORD origCaps, DDRAWI_DIRECTDRAW_LCL* ddLcl);
 		virtual ~TagSurface() override;
 
 		static TagSurface* get(CompatRef<IDirectDraw> dd);
@@ -26,7 +27,7 @@ namespace DDraw
 	private:
 		static HRESULT create(CompatRef<IDirectDraw> dd);
 
-		void* m_ddObject;
+		DDRAWI_DIRECTDRAW_LCL* m_ddLcl;
 		HWND m_fullscreenWindow;
 		LONG m_fullscreenWindowStyle;
 		LONG m_fullscreenWindowExStyle;