Fix incorrect usage of COBJMACROS.
diff --git a/include/d3dx8core.h b/include/d3dx8core.h
index 9011757..7d33ec0 100644
--- a/include/d3dx8core.h
+++ b/include/d3dx8core.h
@@ -64,7 +64,7 @@
DECLARE_INTERFACE_(ID3DXBuffer,IUnknown) { ID3DXBuffer_METHODS };
#undef INTERFACE
-#ifdef COBJMACROS
+#if !defined(__cplusplus) || defined(CINTERFACE)
/*** IUnknown methods ***/
#define ID3DXBuffer_QueryInterface(p,a,b) (p)->lpVtbl->QueryInterface(p,a,b)
#define ID3DXBuffer_AddRef(p) (p)->lpVtbl->AddRef(p)
@@ -87,7 +87,7 @@
DECLARE_INTERFACE_(ID3DXFont,IUnknown) { ID3DXFont_METHODS };
#undef INTERFACE
-#ifdef COBJMACROS
+#if !defined(__cplusplus) || defined(CINTERFACE)
/*** IUnknown methods ***/
#define ID3DXFont_QueryInterface(p,a,b) (p)->lpVtbl->QueryInterface(p,a,b)
#define ID3DXFont_AddRef(p) (p)->lpVtbl->AddRef(p)