diff --git a/demos/demo_xcb.h b/demos/demo_xcb.h
index 6da32b6b..e30bb642 100644
--- a/demos/demo_xcb.h
+++ b/demos/demo_xcb.h
@@ -164,6 +164,8 @@ static inline struct demo_window *demo_window_create(struct demo *demo, const ch
 
     xcb_map_window(demo->connection, window->window);
 
+    xcb_flush(demo->connection);
+
     return window;
 }