diff --git a/reactos/dll/directx/d3d9/d3d9.h b/reactos/dll/directx/d3d9/d3d9.h
deleted file mode 100644
index ba1f5287713..00000000000
--- a/reactos/dll/directx/d3d9/d3d9.h
+++ /dev/null
@@ -1,3 +0,0 @@
-#include <windows.h>
-
-#define DLLAPI __declspec(dllexport)
diff --git a/reactos/dll/directx/d3d9/d3d9_helpers.c b/reactos/dll/directx/d3d9/d3d9_helpers.c
index 53f8db80528..7aa331e2c4d 100644
--- a/reactos/dll/directx/d3d9/d3d9_helpers.c
+++ b/reactos/dll/directx/d3d9/d3d9_helpers.c
@@ -38,7 +38,7 @@ BOOL ReadRegistryValue(IN DWORD ValueType, IN LPCSTR ValueName, OUT LPBYTE DataB
     return TRUE;
 }
 
-HRESULT SafeFormatString(OUT LPSTR Buffer, IN LONG BufferSize, IN LPCSTR FormatString, ... )
+HRESULT SafeFormatString(OUT LPSTR Buffer, IN DWORD BufferSize, IN LPCSTR FormatString, ... )
 {
     DWORD BytesWritten;
     va_list vargs;
diff --git a/reactos/dll/directx/d3d9/d3d9_helpers.h b/reactos/dll/directx/d3d9/d3d9_helpers.h
index 5e8d54cfe8a..a7556e9653f 100644
--- a/reactos/dll/directx/d3d9/d3d9_helpers.h
+++ b/reactos/dll/directx/d3d9/d3d9_helpers.h
@@ -16,7 +16,7 @@
 BOOL ReadRegistryValue(IN DWORD ValueType, IN LPCSTR ValueName, OUT LPBYTE DataBuffer, IN OUT LPDWORD DataBufferSize);
 
 /* Safe string formatting */
-HRESULT SafeFormatString(IN OUT LPSTR Buffer, IN LONG BufferSize, IN LPCSTR FormatString, ... );
+HRESULT SafeFormatString(IN OUT LPSTR Buffer, IN DWORD BufferSize, IN LPCSTR FormatString, ... );
 HRESULT SafeCopyString(OUT LPSTR Dst, IN DWORD DstSize, IN LPCSTR Src);
 HRESULT SafeAppendString(IN OUT LPSTR Dst, IN DWORD DstSize, IN LPCSTR Src);