diff --git a/src/Tests/WidgetIntegrationTest.php b/src/Tests/WidgetIntegrationTest.php
index b0a4058..802561a 100644
--- a/src/Tests/WidgetIntegrationTest.php
+++ b/src/Tests/WidgetIntegrationTest.php
@@ -80,6 +80,71 @@ class WidgetIntegrationTest extends FacetWebTestBase {
   }
 
   /**
+   * Tests submitting multiple items at the same time..
+   */
+  public function testMultipleCheckboxItems() {
+    $id = 'palau';
+    $name = 'Palau owl';
+    $facet_add_page = 'admin/config/search/facets/add-facet';
+
+    // Create a new facet.
+    $this->drupalGet($facet_add_page);
+    $form_values = [
+      'id' => $id,
+      'status' => 1,
+      'url_alias' => $id,
+      'name' => $name,
+      'facet_source_id' => 'search_api_views:search_api_test_view:page_1',
+      'facet_source_configs[search_api_views:search_api_test_view:page_1][field_identifier]' => 'keywords',
+    ];
+    $this->drupalPostForm(NULL, ['facet_source_id' => 'search_api_views:search_api_test_view:page_1'], $this->t('Configure facet source'));
+    $this->drupalPostForm(NULL, $form_values, $this->t('Save'));
+    $this->drupalPostForm(NULL, ['widget' => 'checkbox'], $this->t('Save'));
+
+    // Place a block.
+    $block_values = [
+      'plugin_id' => 'facet_block:' . $id,
+      'settings' => [
+        'region' => 'footer',
+        'id' => str_replace('_', '-', $id),
+      ],
+    ];
+    $this->drupalPlaceBlock($block_values['plugin_id'], $block_values['settings']);
+
+    // Go to the view, check that all results are displayed.
+    $this->drupalGet('search-api-test-fulltext');
+    $this->assertText('Displaying 5 search results');
+
+    // Filter by the grape keyword.
+    $edit = ['keywords[grape]' => 'grape'];
+    $this->drupalPostForm(NULL, $edit, $this->t('submit'));
+    $this->assertFieldChecked('edit-keywords-grape');
+    $this->assertText('Displaying 3 search results');
+
+    // Add apple to the filter as well.
+    $edit = ['keywords[grape]' => 'grape', 'keywords[apple]' => 'apple'];
+    $this->drupalPostForm(NULL, $edit, $this->t('submit'));
+    $this->assertText('Displaying 3 search results');
+    $this->assertFieldChecked('edit-keywords-apple');
+    $this->assertFieldChecked('edit-keywords-grape');
+
+    // Reset the filters back to default and make sure that the original 5
+    // results are displayed again.
+    $this->drupalPostForm(NULL, [], $this->t('submit'));
+    $this->assertText('Displaying 5 search results');
+    $this->assertNoFieldChecked('edit-keywords-apple');
+    $this->assertNoFieldChecked('edit-keywords-grape');
+
+    // Filter on both grape and apple at once and check that those are now
+    // checked.
+    $edit = ['keywords[grape]' => 'grape', 'keywords[apple]' => 'apple'];
+    $this->drupalPostForm(NULL, $edit, $this->t('submit'));
+    $this->assertText('Displaying 3 search results');
+    $this->assertFieldChecked('edit-keywords-apple');
+    $this->assertFieldChecked('edit-keywords-grape');
+  }
+
+  /**
    * Tests multiple checkbox widgets.
    */
   public function testMultipleCheckboxWidget() {