diff --git a/src/backend/wayland/wl_xdg.c b/src/backend/wayland/wl_xdg.c
index ea90a85..54aa08e 100644
--- a/src/backend/wayland/wl_xdg.c
+++ b/src/backend/wayland/wl_xdg.c
@@ -21,6 +21,7 @@
 #include <WINGs/WINGsP.h>
 
 /* Forward declarations for functions defined in other wl_*.c files */
+extern void W_UnregisterBacking(unsigned long id);
 void view_attach_scene_destroy_listener(struct wl_toplevel_view *view);
 void wl_pointer_warp_to(int x, int y);
 void wm_dock_app_add(struct wl_toplevel_view *v);
@@ -237,9 +238,17 @@ handle_toplevel_map(struct wl_listener *listener, void *data)
     int is_popup = (app_id_check && strcmp(app_id_check, "wings-popup") == 0);
 
     if (app_id_check && strcmp(app_id_check, "WINGs") == 0) {
-        struct wl_frame_buf *_fb;
-        wl_list_for_each(_fb, &wl_state.frame_list, link) {
+        struct wl_frame_buf *_fb, *_next;
+        wl_list_for_each_safe(_fb, _next, &wl_state.frame_list, link) {
             if (_fb->id >= 0x20000000 && !wl_find_view_by_id(_fb->id)) {
+                /* Stale WINGs frame_buf from a previous session whose
+                 * parent toplevel no longer exists — clean it up. */
+                if (_fb->parent_id && !frame_buf_find(_fb->parent_id)) {
+                    W_UnregisterBacking(_fb->id);
+                    wl_list_remove(&_fb->link);
+                    wlr_buffer_drop(&_fb->base);
+                    continue;
+                }
                 wwarning("wl_backend: WINGs dialog id 0x%lx", (unsigned long)_fb->id);
                 view->id = _fb->id;
                 view->frame_id = _fb->parent_id;