diff --git a/packages/react/src/avatar/fallback/AvatarFallback.test.tsx b/packages/react/src/avatar/fallback/AvatarFallback.test.tsx
index 04138d990d..77e409a7e8 100644
--- a/packages/react/src/avatar/fallback/AvatarFallback.test.tsx
+++ b/packages/react/src/avatar/fallback/AvatarFallback.test.tsx
@@ -1,7 +1,8 @@
 import * as React from 'react';
 import { Mock } from 'vitest';
 import { Avatar } from '@base-ui-components/react/avatar';
-import { describeConformance, createRenderer } from '#test-utils';
+import { waitFor } from '@mui/internal-test-utils';
+import { describeConformance, createRenderer, isJSDOM } from '#test-utils';
 import { useImageLoadingStatus } from '../image/useImageLoadingStatus';
 
 vi.mock('../image/useImageLoadingStatus');
@@ -30,7 +31,9 @@ describe('<Avatar.Fallback />', () => {
       </Avatar.Root>,
     );
 
-    expect(queryByTestId('fallback')).to.equal(null);
+    await waitFor(() => {
+      expect(queryByTestId('fallback')).to.equal(null);
+    });
   });
 
   it('should render the fallback if the image fails to load', async () => {
@@ -43,10 +46,12 @@ describe('<Avatar.Fallback />', () => {
       </Avatar.Root>,
     );
 
-    expect(queryByText('AC')).to.not.equal(null);
+    await waitFor(() => {
+      expect(queryByText('AC')).not.to.equal(null);
+    });
   });
 
-  describe('prop: delay', () => {
+  describe.skipIf(!isJSDOM)('prop: delay', () => {
     const { clock, render: renderFakeTimers } = createRenderer();
 
     clock.withFakeTimers();
diff --git a/packages/react/src/menu/root/MenuRoot.test.tsx b/packages/react/src/menu/root/MenuRoot.test.tsx
index c39daab55b..ed74942145 100644
--- a/packages/react/src/menu/root/MenuRoot.test.tsx
+++ b/packages/react/src/menu/root/MenuRoot.test.tsx
@@ -1135,9 +1135,9 @@ describe('<Menu.Root />', () => {
       });
     });
 
-    it('should close the menu when the trigger is no longer hovered', async () => {
+    it.skipIf(!isJSDOM)('should close the menu when the trigger is no longer hovered', async () => {
       const { getByRole, queryByRole } = await render(
-        <Menu.Root openOnHover delay={0}>
+        <Menu.Root openOnHover delay={0} modal={false}>
           <Menu.Trigger>Open</Menu.Trigger>
           <Menu.Portal>
             <Menu.Positioner>