diff --git a/gdk/win32/gdkdisplay-win32.c b/gdk/win32/gdkdisplay-win32.c
index 8bdb9331e0..75fde08659 100644
--- a/gdk/win32/gdkdisplay-win32.c
+++ b/gdk/win32/gdkdisplay-win32.c
@@ -229,7 +229,7 @@ gdk_display_get_name (GdkDisplay *display)
   DWORD session_id;
   char *display_name;
   static const char *display_name_cache = NULL;
-  typedef BOOL (* PFN_ProcessIdToSessionId) (DWORD, DWORD *);
+  typedef BOOL (WINAPI *PFN_ProcessIdToSessionId) (DWORD, DWORD *);
   PFN_ProcessIdToSessionId processIdToSessionId;
 
   g_return_val_if_fail (GDK_IS_DISPLAY (display), NULL);