diff --git a/CMakeLists.txt b/CMakeLists.txt
index ba7af5ee..8661dabf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -430,6 +430,7 @@ if (ISLE_USE_SMARTHEAP)
 endif()
 foreach(tgt IN LISTS lego1_targets)
   target_link_libraries(${tgt} PRIVATE $<$<BOOL:${ISLE_USE_DX5}>:DirectX5::DirectX5>)
+  target_compile_definitions(${tgt} PRIVATE $<$<BOOL:${ISLE_USE_DX5}>:DIRECTX5_SDK>)
 endforeach()
 
 # Make sure filenames are ALL CAPS
diff --git a/LEGO1/tgl/d3drm/impl.h b/LEGO1/tgl/d3drm/impl.h
index c49ffd1a..413f7110 100644
--- a/LEGO1/tgl/d3drm/impl.h
+++ b/LEGO1/tgl/d3drm/impl.h
@@ -5,6 +5,12 @@
 
 #include <d3drm.h>
 
+#ifdef DIRECTX5_SDK
+typedef DWORD LPD3DRM_APPDATA;
+#else
+typedef LPVOID LPD3DRM_APPDATA;
+#endif
+
 // Forward declare D3D types
 struct IDirect3DRM2;
 struct IDirect3DRMDevice2;
diff --git a/LEGO1/tgl/d3drm/texture.cpp b/LEGO1/tgl/d3drm/texture.cpp
index b0ee3813..a51a5c0b 100644
--- a/LEGO1/tgl/d3drm/texture.cpp
+++ b/LEGO1/tgl/d3drm/texture.cpp
@@ -15,16 +15,16 @@ void TextureDestroyCallback(IDirect3DRMObject* pObject, void* pArg);
 // FUNCTION: LEGO1 0x100a12a0
 Result TextureImpl::SetImage(IDirect3DRMTexture* pSelf, TglD3DRMIMAGE* pImage)
 {
-	unsigned long appData;
+	void* appData;
 	Result result;
 
-	appData = reinterpret_cast<unsigned long>(pImage);
+	appData = pImage;
 
 	// This is here because in the original code they asserted
 	// on the return value being NULL.
 	TextureGetImage(pSelf);
 
-	result = ResultVal(pSelf->SetAppData(appData));
+	result = ResultVal(pSelf->SetAppData((LPD3DRM_APPDATA) appData));
 	if (Succeeded(result) && pImage) {
 		result = ResultVal(pSelf->AddDestroyCallback(TextureDestroyCallback, NULL));
 		if (!Succeeded(result)) {
diff --git a/LEGO1/tgl/d3drm/view.cpp b/LEGO1/tgl/d3drm/view.cpp
index 457c54d2..b9fca8e9 100644
--- a/LEGO1/tgl/d3drm/view.cpp
+++ b/LEGO1/tgl/d3drm/view.cpp
@@ -50,7 +50,7 @@ Result ViewImpl::ViewportCreateAppData(IDirect3DRM2* pDevice, IDirect3DRMViewpor
 {
 	ViewportAppData* data = new ViewportAppData(pDevice);
 	data->m_pCamera = pCamera;
-	Result result = ResultVal(pView->SetAppData(reinterpret_cast<unsigned long>(data)));
+	Result result = ResultVal(pView->SetAppData(reinterpret_cast<LPD3DRM_APPDATA>(data)));
 	if (Succeeded(result)) {
 		result = ResultVal(pView->AddDestroyCallback(ViewportDestroyCallback, data));
 	}
diff --git a/LEGO1/viewmanager/viewmanager.cpp b/LEGO1/viewmanager/viewmanager.cpp
index 3531381c..c0691587 100644
--- a/LEGO1/viewmanager/viewmanager.cpp
+++ b/LEGO1/viewmanager/viewmanager.cpp
@@ -29,7 +29,7 @@ float g_unk0x1010105c = 0.000125F;
 // GLOBAL: LEGO1 0x10101060
 float g_elapsedSeconds = 0;
 
-inline void SetAppData(ViewROI* p_roi, DWORD data);
+inline void SetAppData(ViewROI* p_roi, LPD3DRM_APPDATA data);
 inline undefined4 GetD3DRM(IDirect3DRM2*& d3drm, Tgl::Renderer* pRenderer);
 inline undefined4 GetFrame(IDirect3DRMFrame2*& frame, Tgl::Group* scene);
 
@@ -165,7 +165,7 @@ void ViewManager::UpdateROIDetailBasedOnLOD(ViewROI* p_roi, int p_und)
 
 		if (lod->GetUnknown0x08() & ViewLOD::c_bit4) {
 			scene->Add((Tgl::MeshBuilder*) group);
-			SetAppData(p_roi, (DWORD) p_roi);
+			SetAppData(p_roi, reinterpret_cast<LPD3DRM_APPDATA>(p_roi));
 		}
 	}
 	else {
@@ -187,7 +187,7 @@ void ViewManager::UpdateROIDetailBasedOnLOD(ViewROI* p_roi, int p_und)
 
 		if (meshBuilder != NULL) {
 			group->Add(meshBuilder);
-			SetAppData(p_roi, (DWORD) p_roi);
+			SetAppData(p_roi, reinterpret_cast<LPD3DRM_APPDATA>(p_roi));
 			p_roi->SetUnknown0xe0(p_und);
 			return;
 		}
@@ -533,7 +533,7 @@ ViewROI* ViewManager::Pick(Tgl::View* p_view, unsigned long x, unsigned long y)
 	return result;
 }
 
-inline void SetAppData(ViewROI* p_roi, DWORD data)
+inline void SetAppData(ViewROI* p_roi, LPD3DRM_APPDATA data)
 {
 	IDirect3DRMFrame2* frame = NULL;