diff --git a/sway/desktop/xdg_shell.c b/sway/desktop/xdg_shell.c
--- a/sway/desktop/xdg_shell.c
+++ b/sway/desktop/xdg_shell.c
@@ -19,6 +19,13 @@
 #include "sway/tree/workspace.h"
 #include "sway/xdg_decoration.h"
 
+// PRIVATE EXPERIMENTAL: exact primary-popup reservation diagnostic only.
+// WHY/CONTRACT: actual XDG parent role scopes only this native factory call.
+// INVARIANT: all existing NULL cleanup/Wayland behavior remains native.
+extern struct wlr_scene_tree *smx_oom_popup_tree_create(
+    struct wlr_scene_tree *parent, const char *role,
+    const void *xdg, const void *xdg_parent);
+
 static struct sway_xdg_popup *popup_create(
 	struct wlr_xdg_popup *wlr_popup, struct sway_view *view,
 	struct wlr_scene_tree *parent, struct wlr_scene_tree *image_capture_parent);
@@ -90,7 +97,11 @@
 	popup->wlr_xdg_popup = wlr_popup;
 	popup->view = view;
 
-	popup->scene_tree = wlr_scene_tree_create(parent);
+	struct wlr_xdg_surface *xdg_parent =
+        wlr_xdg_surface_try_from_wlr_surface(wlr_popup->parent);
+    popup->scene_tree = smx_oom_popup_tree_create(parent,
+        xdg_parent && xdg_parent->role == WLR_XDG_SURFACE_ROLE_POPUP ?
+            "nested_popup" : "root_popup", xdg_surface, xdg_parent);
 	if (!popup->scene_tree) {
 		free(popup);
 		return NULL;