diff --git a/reactos/include/psdk/wingdi.h b/reactos/include/psdk/wingdi.h
index ef233abde14..b7bd62b1aae 100644
--- a/reactos/include/psdk/wingdi.h
+++ b/reactos/include/psdk/wingdi.h
@@ -2917,6 +2917,7 @@ BOOL WINAPI FlattenPath(HDC);
 BOOL WINAPI FloodFill(HDC,int,int,COLORREF);
 BOOL WINAPI GdiAlphaBlend(HDC,int,int,int,int,HDC,int,int,int,int,BLENDFUNCTION);
 BOOL WINAPI GdiComment(HDC,UINT,const BYTE*);
+DEVMODEW* WINAPI GdiConvertToDevmodeW(const DEVMODEA *);
 BOOL WINAPI GdiFlush(void);
 DWORD WINAPI GdiGetBatchLimit(void);
 DWORD WINAPI GdiSetBatchLimit(DWORD);