Index: buildconfig/Setup.SDL1.in
--- buildconfig/Setup.SDL1.in.orig
+++ buildconfig/Setup.SDL1.in
@@ -50,6 +50,7 @@ cdrom src_c/cdrom.c $(SDL) $(DEBUG)
 color src_c/color.c $(SDL) $(DEBUG)
 constants src_c/constants.c $(SDL) $(DEBUG)
 display src_c/display.c $(SDL) $(DEBUG)
+display src_c/display.c $(SDL) $(DEBUG) -I${X11BASE}/include
 event src_c/event.c $(SDL) $(DEBUG)
 fastevent src_c/fastevent.c src_c/fastevents.c $(SDL) $(DEBUG)
 key src_c/key.c $(SDL) $(DEBUG)