Set window user data using separate function
diff --git a/clients/image.c b/clients/image.c
index 8493071..52621e9 100644
--- a/clients/image.c
+++ b/clients/image.c
@@ -223,8 +223,9 @@
 	 * allocation scheme here.  Or maybe just a real toolkit. */
 	image->key = key + 100;
 
-	window_set_redraw_handler(image->window, redraw_handler, image);
-	window_set_keyboard_focus_handler(image->window, keyboard_focus_handler, image);
+	window_set_user_data(image->window, image);
+	window_set_redraw_handler(image->window, redraw_handler);
+	window_set_keyboard_focus_handler(image->window, keyboard_focus_handler);
 
 	image_draw(image);