diff --git a/dlls/d3dx8/d3dx8core_private.h b/dlls/d3dx8/d3dx8core_private.h
index 7b83ffa7dff..fb98b38e4ab 100644
--- a/dlls/d3dx8/d3dx8core_private.h
+++ b/dlls/d3dx8/d3dx8core_private.h
@@ -54,24 +54,10 @@ struct ID3DXBufferImpl
   DWORD          bufferSize;
 };
 
-/* IUnknown: */
-extern HRESULT WINAPI ID3DXBufferImpl_QueryInterface(LPD3DXBUFFER iface, REFIID refiid, LPVOID *obj);
-extern ULONG WINAPI   ID3DXBufferImpl_AddRef(LPD3DXBUFFER iface);
-extern ULONG WINAPI   ID3DXBufferImpl_Release(LPD3DXBUFFER iface);
-
-/* ID3DXBuffer: */
-extern LPVOID WINAPI ID3DXBufferImpl_GetBufferPointer(LPD3DXBUFFER iface);
-extern DWORD WINAPI  ID3DXBufferImpl_GetBufferSize(LPD3DXBUFFER iface);
-
 /* --------- */
 /* ID3DXFont */
 /* --------- */
 
-/*****************************************************************************
- * Predeclare the interface implementation structures
- */
-extern const ID3DXFontVtbl D3DXFont_Vtbl;
-
 /*****************************************************************************
  * ID3DXFontImpl implementation structure
  */
@@ -84,12 +70,4 @@ struct ID3DXFontImpl
   /* ID3DXFont fields */
 };
 
-/* IUnknown: */
-extern HRESULT WINAPI ID3DXFontImpl_QueryInterface(LPD3DXFONT iface, REFIID refiid, LPVOID *obj);
-extern ULONG WINAPI   ID3DXFontImpl_AddRef(LPD3DXFONT iface);
-extern ULONG WINAPI   ID3DXFontImpl_Release(LPD3DXFONT iface);
-
-/* ID3DXFont: */
-extern INT WINAPI     ID3DXFontImpl_DrawTextA(LPCSTR pString, INT Count, LPRECT pRect, DWORD Format, D3DCOLOR Color); 
-
 #endif /*__WINE_D3DX8CORE_PRIVATE_H */
diff --git a/dlls/d3dx8/d3dxbuffer.c b/dlls/d3dx8/d3dxbuffer.c
index a07618b2d73..6d0a780a7fc 100644
--- a/dlls/d3dx8/d3dxbuffer.c
+++ b/dlls/d3dx8/d3dxbuffer.c
@@ -23,6 +23,7 @@
 
 #include <stdarg.h>
 
+#define COBJMACROS
 #include "windef.h"
 #include "winbase.h"
 #include "winuser.h"
@@ -35,12 +36,12 @@
 WINE_DEFAULT_DEBUG_CHANNEL(d3d);
 
 /* ID3DXBuffer IUnknown parts follow: */
-HRESULT WINAPI ID3DXBufferImpl_QueryInterface(LPD3DXBUFFER iface, REFIID riid, LPVOID* ppobj) {
+static HRESULT WINAPI ID3DXBufferImpl_QueryInterface(LPD3DXBUFFER iface, REFIID riid, LPVOID* ppobj) {
   ID3DXBufferImpl *This = (ID3DXBufferImpl *)iface;
   
   if (IsEqualGUID(riid, &IID_IUnknown)
       || IsEqualGUID(riid, &IID_ID3DXBuffer)) {
-    ID3DXBufferImpl_AddRef(iface);
+    IUnknown_AddRef(iface);
     *ppobj = This;
     return D3D_OK;
   }
@@ -49,7 +50,7 @@ HRESULT WINAPI ID3DXBufferImpl_QueryInterface(LPD3DXBUFFER iface, REFIID riid, L
   return E_NOINTERFACE;
 }
 
-ULONG WINAPI ID3DXBufferImpl_AddRef(LPD3DXBUFFER iface) {
+static ULONG WINAPI ID3DXBufferImpl_AddRef(LPD3DXBUFFER iface) {
   ID3DXBufferImpl *This = (ID3DXBufferImpl *)iface;
   ULONG ref = InterlockedIncrement(&This->ref);
 
@@ -58,7 +59,7 @@ ULONG WINAPI ID3DXBufferImpl_AddRef(LPD3DXBUFFER iface) {
   return ref;
 }
 
-ULONG WINAPI ID3DXBufferImpl_Release(LPD3DXBUFFER iface) {
+static ULONG WINAPI ID3DXBufferImpl_Release(LPD3DXBUFFER iface) {
   ID3DXBufferImpl *This = (ID3DXBufferImpl *)iface;
   ULONG ref = InterlockedDecrement(&This->ref);
 
@@ -72,12 +73,12 @@ ULONG WINAPI ID3DXBufferImpl_Release(LPD3DXBUFFER iface) {
 }
 
 /* ID3DXBuffer Interface follow: */
-LPVOID WINAPI ID3DXBufferImpl_GetBufferPointer(LPD3DXBUFFER iface) {
+static LPVOID WINAPI ID3DXBufferImpl_GetBufferPointer(LPD3DXBUFFER iface) {
   ID3DXBufferImpl *This = (ID3DXBufferImpl *)iface;
   return This->buffer;
 }
 
-DWORD WINAPI ID3DXBufferImpl_GetBufferSize(LPD3DXBUFFER iface) {
+static DWORD WINAPI ID3DXBufferImpl_GetBufferSize(LPD3DXBUFFER iface) {
   ID3DXBufferImpl *This = (ID3DXBufferImpl *)iface;
   return This->bufferSize;
 }