diff --git a/reactos/dll/win32/gdi32/misc/wingl.c b/reactos/dll/win32/gdi32/misc/wingl.c
index d08a8e6f30e..8f0c9e524c6 100644
--- a/reactos/dll/win32/gdi32/misc/wingl.c
+++ b/reactos/dll/win32/gdi32/misc/wingl.c
@@ -28,11 +28,11 @@
 
 
 
-typedef int  (*CHOOSEPIXELFMT) (HDC, CONST PIXELFORMATDESCRIPTOR *);
-typedef BOOL (*SETPIXELFMT) (HDC, int, CONST PIXELFORMATDESCRIPTOR *);
-typedef BOOL (*SWAPBUFFERS) (HDC hdc);
-typedef int  (*DESCRIBEPIXELFMT) (HDC, int, UINT, LPPIXELFORMATDESCRIPTOR);
-typedef int  (*GETPIXELFMT) (HDC);
+typedef int  STDCALL (*CHOOSEPIXELFMT) (HDC, CONST PIXELFORMATDESCRIPTOR *);
+typedef BOOL STDCALL (*SETPIXELFMT) (HDC, int, CONST PIXELFORMATDESCRIPTOR *);
+typedef BOOL STDCALL (*SWAPBUFFERS) (HDC hdc);
+typedef int  STDCALL (*DESCRIBEPIXELFMT) (HDC, int, UINT, LPPIXELFORMATDESCRIPTOR);
+typedef int  STDCALL (*GETPIXELFMT) (HDC);
 
 
 static CHOOSEPIXELFMT    glChoosePixelFormat   = NULL;