diff --git a/src/gui/src/helpers/launch_app.js b/src/gui/src/helpers/launch_app.js
index 90660c46f..76ea57aff 100644
--- a/src/gui/src/helpers/launch_app.js
+++ b/src/gui/src/helpers/launch_app.js
@@ -558,6 +558,13 @@ const launch_app = async (options) => {
         // Add locale to URL
         iframe_url.searchParams.append('puter.locale', window.locale);
 
+        // Newer IPC dialogs this GUI can answer, comma-separated. The SDK
+        // consults this before posting a message an older GUI has no handler
+        // for: such a message is never replied to, and a reply timeout can't
+        // stand in for the check because legitimate replies only arrive when
+        // the user closes the dialog.
+        iframe_url.searchParams.append('puter.gui_features', 'feedback-dialog');
+
         // Add options.args to URL
         iframe_url.searchParams.append('puter.args', JSON.stringify(options.args ?? {}));
 
diff --git a/src/puter-js/src/modules/UI.js b/src/puter-js/src/modules/UI.js
index efaa65aa4..14b327b78 100644
--- a/src/puter-js/src/modules/UI.js
+++ b/src/puter-js/src/modules/UI.js
@@ -1688,6 +1688,18 @@ class UI extends EventListener {
      */
     async showFeedbackDialog () {
         if ( this.env === 'app' ) {
+            // The host GUI advertises the IPC dialogs it can answer via
+            // `puter.gui_features` on the app iframe's URL (see
+            // launch_app.js). A GUI that predates this feature has no
+            // handler for the message and would never reply, hanging this
+            // never-rejecting promise forever — and a reply timeout can't
+            // stand in for the check, because a legitimate reply only
+            // arrives when the user closes the dialog.
+            const features = new URLSearchParams(globalThis.location?.search ?? '')
+                .get('puter.gui_features')?.split(',') ?? [];
+            if ( ! features.includes('feedback-dialog') ) {
+                return false;
+            }
             const result = await this.#postMessageAsync('showFeedbackDialog', {});
             return result?.sent === true;
         }