diff --git a/core/modules/media_library/tests/src/FunctionalJavascript/WidgetOverflowTest.php b/core/modules/media_library/tests/src/FunctionalJavascript/WidgetOverflowTest.php
index 75c8aa54e7..23b931b6e0 100644
--- a/core/modules/media_library/tests/src/FunctionalJavascript/WidgetOverflowTest.php
+++ b/core/modules/media_library/tests/src/FunctionalJavascript/WidgetOverflowTest.php
@@ -53,7 +53,7 @@ protected function setUp() {
   }
 
   /**
-   * Tests overflow validation with standard UI.
+   * Tests overflow validation.
    *
    * @dataProvider overflowProvider
    */
@@ -106,6 +106,62 @@ public function testWidgetOverflow($advanced_ui, $button_text) {
     $this->pressInsertSelected('Added 2 media items.');
   }
 
+  /**
+   * Tests overflow validation skips fields with unlimited cardinality.
+   *
+   * @dataProvider overflowProvider
+   */
+  public function testUnlimitedCardinality($advanced_ui, $button_text) {
+    $this->config('media_library.settings')->set('advanced_ui', $advanced_ui)->save();
+    $assert_session = $this->assertSession();
+    $page = $this->getSession()->getPage();
+    $driver = $this->getSession()->getDriver();
+    /** @var \Drupal\Core\File\FileSystemInterface $file_system */
+    $file_system = $this->container->get('file_system');
+    // Visit a node create page and open the media library.
+    $this->drupalGet('node/add/basic_page');
+    $this->openMediaLibraryForField('field_unlimited_media');
+    $this->switchToMediaType('Three');
+    $assert_session->pageTextContains('Add or select media');
+    $assert_session->fieldExists('Add files');
+    // Create a list of new files to upload.
+    $filenames = [];
+    $remote_paths = [];
+    foreach (range(1, 5) as $i) {
+      $path = $file_system->copy($this->image->uri, 'public://');
+      $filenames[] = $file_system->basename($path);
+      $remote_paths[] = $driver->uploadFileAndGetRemoteFilePath($file_system->realpath($path));
+    }
+    $page->findField('Add files')->setValue(implode("\n", $remote_paths));
+    // Assert the media item fields are shown and the vertical tabs are no
+    // longer shown.
+    $this->assertMediaAdded();
+    // Assert all files have been added.
+    foreach (range(0, 4) as $i) {
+      $assert_session->fieldValueEquals("media[$i][fields][name][0][value]", $filenames[$i]);
+      $page->fillField("media[$i][fields][field_media_test_image][0][alt]", $filenames[$i]);
+    }
+    // When the user is returned to the media library there should not
+    // be a warning message.
+    $buttons = $assert_session->elementExists('css', '.ui-dialog-buttonpane');
+    $buttons->pressButton($button_text);
+
+    if ($button_text === 'Save and insert') {
+      $this->waitForText('Added 5 media items.');
+    }
+    else {
+      $result = $buttons->waitFor(10, function ($buttons) {
+        /** @var \Behat\Mink\Element\NodeElement $buttons */
+        return $buttons->findButton('Insert selected');
+      });
+      $this->assertNotEmpty($result);
+      $assert_session->elementNotExists('css', '.messages--warning');
+      // When the user tries insert more items than allowed, the user is returned
+      // to the media library with an error message.
+      $this->pressInsertSelected('Added 5 media items.');
+    }
+  }
+
   /**
    * Data provider for ::testWidgetOverflow().
    *