diff --git a/scripts/claude-native-stub.js b/scripts/claude-native-stub.js
index 8451257..2da1af0 100644
--- a/scripts/claude-native-stub.js
+++ b/scripts/claude-native-stub.js
@@ -13,6 +13,8 @@ function getWindow() {
     const { BrowserWindow } = require('electron');
     const focused = BrowserWindow.getFocusedWindow();
     if (focused) return focused;
+    // TODO: Fallback may return a popup window; callers like
+    // getIsMaximized() may behave unexpectedly on popups.
     const win = BrowserWindow.getAllWindows().find(
       (w) => !w.isDestroyed()
     );
diff --git a/scripts/frame-fix-wrapper.js b/scripts/frame-fix-wrapper.js
index 0369922..cd41bc5 100644
--- a/scripts/frame-fix-wrapper.js
+++ b/scripts/frame-fix-wrapper.js
@@ -139,6 +139,7 @@ Module.prototype.require = function(id) {
       if (process.platform === 'linux') {
         // Hide menu bar on all existing windows after menu is set
         for (const win of module.BrowserWindow.getAllWindows()) {
+          if (win.isDestroyed()) continue;
           win.setMenuBarVisibility(false);
         }
         console.log('[Frame Fix] Menu bar hidden on all windows');