diff --git a/src/backend/wayland/wl_backend.c b/src/backend/wayland/wl_backend.c
index 15e03ef..604e1f5 100644
--- a/src/backend/wayland/wl_backend.c
+++ b/src/backend/wayland/wl_backend.c
@@ -54,6 +54,9 @@
  * Phase 64: zxdg_decoration_manager_v1 advertised; new_toplevel_decoration
  * listener responds immediately with CLIENT_SIDE mode so clients draw their
  * own title bars (no X11 frame rendering in the Wayland path).
+ * Phase 65: prop_get_transient_for implemented — walks xdg_toplevel->parent
+ * chain and returns the synthetic WNativeWindow ID of the parent view so
+ * dialog windows are correctly identified as transients by the policy layer.
  */
 
 #ifdef HAVE_CONFIG_H
@@ -202,6 +205,18 @@ wl_find_view_by_id(WNativeWindow id)
     return NULL;
 }
 
+/* Phase 65: look up the view for a given wlr_xdg_surface pointer. */
+static struct wl_toplevel_view *
+wl_find_view_by_xdg_surface(struct wlr_xdg_surface *surf)
+{
+    struct wl_toplevel_view *v;
+    wl_list_for_each(v, &wl_state.toplevel_list, link) {
+        if (v->xdg_surface == surf)
+            return v;
+    }
+    return NULL;
+}
+
 /*
  * Phase 46: XDG toplevel title changed — update wwin->wm_instance.
  */
@@ -977,7 +992,23 @@ wl_prop_get_wmaker_menu(WNativeWindow win,
 }
 
 static WNativeWindow
-wl_prop_get_transient_for(WNativeWindow win) { (void)win; return WNATIVE_NONE; }
+wl_prop_get_transient_for(WNativeWindow win)
+{
+    /* Phase 65: return the synthetic ID of the parent XDG toplevel, or
+     * WNATIVE_NONE if this surface has no parent.  The wlroots XDG
+     * implementation stores the parent as xdg_surface->toplevel->parent
+     * (a wlr_xdg_surface *).  We walk the view list to find its ID. */
+    struct wl_toplevel_view *v = wl_find_view_by_id(win);
+    if (!v || !v->xdg_surface || !v->xdg_surface->toplevel)
+        return WNATIVE_NONE;
+    struct wlr_xdg_surface *parent = v->xdg_surface->toplevel->parent;
+    if (!parent)
+        return WNATIVE_NONE;
+    struct wl_toplevel_view *pv = wl_find_view_by_xdg_surface(parent);
+    if (!pv)
+        return WNATIVE_NONE;
+    return pv->id;
+}
 
 static int  wl_prop_has_wmaker_menu(WNativeWindow win) { (void)win; return 0; }
 static int  wl_prop_has_gtk_object_path(WNativeWindow win) { (void)win; return 0; }
diff --git a/tests/wl-smoke-test.sh b/tests/wl-smoke-test.sh
index 37cc8a8..986568e 100755
--- a/tests/wl-smoke-test.sh
+++ b/tests/wl-smoke-test.sh
@@ -50,6 +50,8 @@
 #  22. (Phase 64) zxdg_decoration_manager_v1 advertised in global registry;
 #      compositor logs "xdg-decoration-manager created"; new toplevels receive
 #      CLIENT_SIDE mode ("decoration mode=client_side" logged).
+#  23. (Phase 65) prop_get_transient_for returns parent XDG surface ID for
+#      dialog windows (build-only check — weston-simple-shm has no transients).
 #
 # This test grows as wl_backend vtable slots are implemented.
 #