diff --git a/facets.routing.yml b/facets.routing.yml
index 9c08b77..9f26911 100644
--- a/facets.routing.yml
+++ b/facets.routing.yml
@@ -48,8 +48,9 @@ entity.facets_facet_source.edit_form:
     _title: 'Edit facet source configuration'
   requirements:
     _entity_create_access: 'facets_facet'
+
 facets.block.ajax:
-  path: '/facets-block/ajax'
+  path: '/facets-block-ajax'
   defaults:
     _controller: '\Drupal\facets\Controller\FacetBlockAjaxController::ajaxFacetBlockView'
   requirements:
diff --git a/js/dropdown-widget.js b/js/dropdown-widget.js
index 50771d8..1e790c5 100644
--- a/js/dropdown-widget.js
+++ b/js/dropdown-widget.js
@@ -37,6 +37,7 @@
       // Remove the class which we are using for .once().
       $dropdown.removeClass('js-facets-dropdown-links');
 
+      $dropdown.addClass('facets-dropdown');
       $dropdown.addClass('js-facets-dropdown');
 
       var id = $(this).data('drupal-facet-id');
diff --git a/js/facets-views-ajax.js b/js/facets-views-ajax.js
index 3a12506..3f2fac5 100644
--- a/js/facets-views-ajax.js
+++ b/js/facets-views-ajax.js
@@ -1,17 +1,6 @@
 /**
  * @file
- * Facets Views AJAX handling.
- */
-
-/**
- * @name FacetsViewsAjaxSettings
- * @property {String} view_id
- * @property {String} current_display_id
- * @property {String} view_base_path
- */
-
-/**
- * @property {FacetsViewsAjaxSettings[]} drupalSettings.facets_views_ajax
+ * Facets views AJAX handling.
  */
 
 
@@ -120,8 +109,8 @@
     var facets_blocks = facetsBlocks();
 
     // Update facet blocks.
-    var facet_settings = {
-      url: Drupal.url('facets-block/ajax'),
+    let facet_settings = {
+      url: Drupal.url('facets-block-ajax'),
       submit: {
         facet_link: href,
         facets_blocks: facets_blocks
@@ -157,7 +146,7 @@
     }
 
     return update_summary;
-  }
+  };
 
   // Helper function, return facet blocks.
   var facetsBlocks = function () {
@@ -176,7 +165,7 @@
     });
 
     return facets_blocks;
-  }
+  };
 
   /**
    * Overrides beforeSend to trigger facetblocks update on exposed filter change.
diff --git a/src/Controller/FacetBlockAjaxController.php b/src/Controller/FacetBlockAjaxController.php
index e1c148c..72f1478 100644
--- a/src/Controller/FacetBlockAjaxController.php
+++ b/src/Controller/FacetBlockAjaxController.php
@@ -10,6 +10,7 @@ use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\Path\CurrentPathStack;
 use Drupal\Core\PathProcessor\PathProcessorManager;
 use Drupal\Core\Render\RendererInterface;
+use Drupal\Core\Routing\CurrentRouteMatch;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\RequestStack;
@@ -17,7 +18,7 @@ use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\Routing\RouterInterface;
 
 /**
- * Defines a controller to load a view via AJAX.
+ * Defines a controller to load a facet via AJAX.
  */
 class FacetBlockAjaxController extends ControllerBase {
 
@@ -56,6 +57,13 @@ class FacetBlockAjaxController extends ControllerBase {
    */
   protected $pathProcessor;
 
+  /**
+   * The current route match service.
+   *
+   * @var \Drupal\Core\Routing\CurrentRouteMatch
+   */
+  protected $currentRouteMatch;
+
   /**
    * Constructs a FacetBlockAjaxController object.
    *
@@ -68,12 +76,13 @@ class FacetBlockAjaxController extends ControllerBase {
    * @param \Drupal\Core\PathProcessor\PathProcessorManager $pathProcessor
    *   The path processor manager.
    */
-  public function __construct(RendererInterface $renderer, CurrentPathStack $currentPath, RouterInterface $router, PathProcessorManager $pathProcessor) {
+  public function __construct(RendererInterface $renderer, CurrentPathStack $currentPath, RouterInterface $router, PathProcessorManager $pathProcessor, CurrentRouteMatch $currentRouteMatch) {
     $this->storage = $this->entityTypeManager()->getStorage('block');
     $this->renderer = $renderer;
     $this->currentPath = $currentPath;
     $this->router = $router;
     $this->pathProcessor = $pathProcessor;
+    $this->currentRouteMatch = $currentRouteMatch;
   }
 
   /**
@@ -84,7 +93,8 @@ class FacetBlockAjaxController extends ControllerBase {
       $container->get('renderer'),
       $container->get('path.current'),
       $container->get('router'),
-      $container->get('path_processor_manager')
+      $container->get('path_processor_manager'),
+      $container->get('current_route_match')
     );
   }
 
@@ -114,23 +124,18 @@ class FacetBlockAjaxController extends ControllerBase {
       throw new NotFoundHttpException('No facet link or facet blocks found.');
     }
 
-    \Drupal::service('current_route_match')->resetRouteMatch();
+    $this->currentRouteMatch->resetRouteMatch();
     $new_request = Request::create($path);
-    $requestStack = new RequestStack();
+    $request_stack = new RequestStack();
     $processed = $this->pathProcessor->processInbound($path, $new_request);
 
-    // @todo When does this happen?
-    if (empty($processed)) {
-      throw new NotFoundHttpException();
-    }
-
     $this->currentPath->setPath($processed, $new_request);
     $request->attributes->add($this->router->matchRequest($new_request));
-    $requestStack->push($new_request);
+    $request_stack->push($new_request);
 
     $container = \Drupal::getContainer();
-    $container->set('request_stack', $requestStack);
-    $activeFacet = $request->request->get('active_facet');
+    $container->set('request_stack', $request_stack);
+    $active_facet = $request->request->get('active_facet');
 
     // Build the facets blocks found for the current request and update.
     foreach ($facets_blocks as $block_id => $block_selector) {
@@ -142,21 +147,15 @@ class FacetBlockAjaxController extends ControllerBase {
           ->getViewBuilder('block')
           ->view($block_entity);
 
-        /** @var \Drupal\Core\Render\Markup $block_view */
         $block_view = (string) $this->renderer->renderPlain($block_view);
 
         // Make sure we retain the empty wrapper in case of empty facets to fill
         // them up in next request if they have data.
-        if ($block_view) {
-          $response->addCommand(new ReplaceCommand($block_selector, $block_view));
-        }
-        else {
-          $response->addCommand(new HtmlCommand($block_selector, $block_view));
-        }
+        $response->addCommand(new ReplaceCommand($block_selector, $block_view));
       }
     }
 
-    $response->addCommand(new InvokeCommand('[data-block-plugin-id="' . $activeFacet . '"]', 'addClass', ['facet-active']));
+    $response->addCommand(new InvokeCommand('[data-block-plugin-id="' . $active_facet . '"]', 'addClass', ['facet-active']));
 
     $update_summary_block = $request->request->get('update_summary_block');
 
diff --git a/src/FacetManager/DefaultFacetManager.php b/src/FacetManager/DefaultFacetManager.php
index 7e33a30..4ccacce 100644
--- a/src/FacetManager/DefaultFacetManager.php
+++ b/src/FacetManager/DefaultFacetManager.php
@@ -334,7 +334,19 @@ class DefaultFacetManager {
         ];
       }
       else {
-        return [];
+        // If the facet has no results, but it is being rendered trough ajax we
+        // should render a container (that is empty). This is because the
+        // javascript needs to be able to find a div to replace with the new
+        // content.
+        return [
+          [
+            '#type' => 'container',
+            '#attributes' => [
+              'data-drupal-facet-id' => $facet->id(),
+              'class' => 'facet-empty',
+            ],
+          ],
+        ];
       }
     }
 
diff --git a/src/Plugin/Block/FacetBlock.php b/src/Plugin/Block/FacetBlock.php
index bb23da2..ac224cc 100644
--- a/src/Plugin/Block/FacetBlock.php
+++ b/src/Plugin/Block/FacetBlock.php
@@ -94,7 +94,7 @@ class FacetBlock extends BlockBase implements ContainerFactoryPluginInterface {
         'route_parameters' => ['facets_facet' => $facet->id()],
       ];
 
-      if (!empty($build['#use_ajax']) && isset($facet_id)) {
+      if (!empty($build['#use_ajax'])) {
         $build['#attributes']['class'][] = 'block-facets-ajax';
         $build['#attributes']['class'][] = 'js-facet-block-id-' . $this->configuration['block_id'];
       }
diff --git a/tests/src/FunctionalJavascript/AjaxBehaviorTest.php b/tests/src/FunctionalJavascript/AjaxBehaviorTest.php
new file mode 100644
index 0000000..a4c8d71
--- /dev/null
+++ b/tests/src/FunctionalJavascript/AjaxBehaviorTest.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace Drupal\Tests\facets\FunctionalJavascript;
+
+/**
+ * Tests for the JS that powers ajax.
+ *
+ * @group facets
+ */
+class AjaxBehaviorTest extends JsBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+  }
+
+  /**
+   * Tests ajax links.
+   */
+  public function testAjaxLinks() {
+    $this->createFacet('owl');
+    $this->createFacet('duck', 'keywords');
+
+    // Go to the views page.
+    $this->drupalGet('search-api-test-fulltext');
+
+    // Make sure the block is shown on the page.
+    $page = $this->getSession()->getPage();
+    $block_owl = $page->findById('block-owl-block');
+    $block_owl->isVisible();
+    $block_duck = $page->findById('block-duck-block');
+    $block_duck->isVisible();
+  }
+
+  /**
+   * Create a facet.
+   *
+   * @param string $id
+   *   The id of the facet.
+   * @param string $field
+   *   The field name.
+   */
+  protected function createFacet($id, $field = 'type') {
+    $facet_storage = \Drupal::entityTypeManager()->getStorage('facets_facet');
+    // Create and save a facet with a checkbox widget.
+    $facet_storage->create([
+      'id' => $id,
+      'name' => strtoupper($id),
+      'url_alias' => $id,
+      'facet_source_id' => 'search_api:views_page__search_api_test_view__page_1',
+      'field_identifier' => $field,
+      'empty_behavior' => ['behavior' => 'none'],
+      'weight' => 1,
+      'widget' => [
+        'type' => 'links',
+        'config' => [
+          'show_numbers' => TRUE,
+          'soft_limit' => 0,
+        ],
+      ],
+      'processor_configs' => [
+        'url_processor_handler' => [
+          'processor_id' => 'url_processor_handler',
+          'weights' => ['pre_query' => -10, 'build' => -10],
+          'settings' => [],
+        ],
+      ],
+    ])->save();
+    $this->createBlock($id);
+  }
+
+}
diff --git a/tests/src/FunctionalJavascript/JsBase.php b/tests/src/FunctionalJavascript/JsBase.php
new file mode 100644
index 0000000..28b9448
--- /dev/null
+++ b/tests/src/FunctionalJavascript/JsBase.php
@@ -0,0 +1,130 @@
+<?php
+
+namespace Drupal\Tests\facets\FunctionalJavascript;
+
+use Drupal\block\Entity\Block;
+use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
+use Drupal\search_api\Entity\Index;
+
+/**
+ * Tests for the JS that transforms widgets into form elements.
+ */
+abstract class JsBase extends JavascriptTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'views',
+    'search_api',
+    'facets',
+    'facets_search_api_dependency',
+    'block',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+
+    // Create the users used for the tests.
+    $admin_user = $this->drupalCreateUser([
+      'administer search_api',
+      'administer facets',
+      'access administration pages',
+      'administer blocks',
+    ]);
+    $this->drupalLogin($admin_user);
+
+    $this->insertExampleContent();
+  }
+
+  /**
+   * Setup and insert test content.
+   */
+  protected function insertExampleContent() {
+    entity_test_create_bundle('item', NULL, 'entity_test_mulrev_changed');
+    entity_test_create_bundle('article', NULL, 'entity_test_mulrev_changed');
+
+    $entity_test_storage = \Drupal::entityTypeManager()
+      ->getStorage('entity_test_mulrev_changed');
+    $entity_1 = $entity_test_storage->create([
+      'name' => 'foo bar baz',
+      'body' => 'test test',
+      'type' => 'item',
+      'keywords' => ['orange'],
+      'category' => 'item_category',
+    ]);
+    $entity_1->save();
+    $entity_2 = $entity_test_storage->create([
+      'name' => 'foo test',
+      'body' => 'bar test',
+      'type' => 'item',
+      'keywords' => ['orange', 'apple', 'grape'],
+      'category' => 'item_category',
+    ]);
+    $entity_2->save();
+    $entity_3 = $entity_test_storage->create([
+      'name' => 'bar',
+      'body' => 'test foobar',
+      'type' => 'item',
+    ]);
+    $entity_3->save();
+    $entity_4 = $entity_test_storage->create([
+      'name' => 'foo baz',
+      'body' => 'test test test',
+      'type' => 'article',
+      'keywords' => ['apple', 'strawberry', 'grape'],
+      'category' => 'article_category',
+    ]);
+    $entity_4->save();
+    $entity_5 = $entity_test_storage->create([
+      'name' => 'bar baz',
+      'body' => 'foo',
+      'type' => 'article',
+      'keywords' => ['orange', 'strawberry', 'grape', 'banana'],
+      'category' => 'article_category',
+    ]);
+    $entity_5->save();
+
+    $inserted_entities = \Drupal::entityQuery('entity_test_mulrev_changed')
+      ->count()
+      ->execute();
+    $this->assertEquals(5, $inserted_entities, "5 items inserted.");
+
+    /** @var \Drupal\search_api\IndexInterface $index */
+    $index = Index::load('database_search_index');
+    $indexed_items = $index->indexItems();
+    $this->assertEquals(5, $indexed_items, '5 items indexed.');
+  }
+
+  /**
+   * Create and place a facet block in the first sidebar.
+   *
+   * @param string $id
+   *   Create a block for a facet.
+   */
+  protected function createBlock($id) {
+    $config = \Drupal::configFactory();
+    $settings = [
+      'plugin' => 'facet_block:' . $id,
+      'region' => 'sidebar_first',
+      'id' => $id . '_block',
+      'theme' => $config->get('system.theme')->get('default'),
+      'label' => ucfirst($id) . ' block',
+      'visibility' => [],
+      'weight' => 0,
+    ];
+
+    foreach (['region', 'id', 'theme', 'plugin', 'weight', 'visibility'] as $key) {
+      $values[$key] = $settings[$key];
+      // Remove extra values that do not belong in the settings array.
+      unset($settings[$key]);
+    }
+    $values['settings'] = $settings;
+    $block = Block::create($values);
+    $block->save();
+  }
+
+}
diff --git a/tests/src/FunctionalJavascript/WidgetJSTest.php b/tests/src/FunctionalJavascript/WidgetJSTest.php
index 2b606a2..0d67d97 100644
--- a/tests/src/FunctionalJavascript/WidgetJSTest.php
+++ b/tests/src/FunctionalJavascript/WidgetJSTest.php
@@ -2,46 +2,14 @@
 
 namespace Drupal\Tests\facets\FunctionalJavascript;
 
-use Drupal\block\Entity\Block;
 use Drupal\facets\Entity\Facet;
-use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
-use Drupal\search_api\Entity\Index;
 
 /**
  * Tests for the JS that transforms widgets into form elements.
  *
  * @group facets
  */
-class WidgetJSTest extends JavascriptTestBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public static $modules = [
-    'views',
-    'search_api',
-    'facets',
-    'facets_search_api_dependency',
-    'block',
-  ];
-
-  /**
-   * {@inheritdoc}
-   */
-  public function setUp() {
-    parent::setUp();
-
-    // Create the users used for the tests.
-    $admin_user = $this->drupalCreateUser([
-      'administer search_api',
-      'administer facets',
-      'access administration pages',
-      'administer blocks',
-    ]);
-    $this->drupalLogin($admin_user);
-
-    $this->insertExampleContent();
-  }
+class WidgetJSTest extends JsBase {
 
   /**
    * Tests JS interactions in the admin UI.
@@ -251,91 +219,4 @@ class WidgetJSTest extends JavascriptTestBase {
     $this->assertTrue(strpos($current_url, 'search-api-test-fulltext?f%5B0%5D=llama%253Aitem') !== FALSE);
   }
 
-  /**
-   * Setup and insert test content.
-   */
-  protected function insertExampleContent() {
-    entity_test_create_bundle('item', NULL, 'entity_test_mulrev_changed');
-    entity_test_create_bundle('article', NULL, 'entity_test_mulrev_changed');
-
-    $entity_test_storage = \Drupal::entityTypeManager()
-      ->getStorage('entity_test_mulrev_changed');
-    $entity_1 = $entity_test_storage->create([
-      'name' => 'foo bar baz',
-      'body' => 'test test',
-      'type' => 'item',
-      'keywords' => ['orange'],
-      'category' => 'item_category',
-    ]);
-    $entity_1->save();
-    $entity_2 = $entity_test_storage->create([
-      'name' => 'foo test',
-      'body' => 'bar test',
-      'type' => 'item',
-      'keywords' => ['orange', 'apple', 'grape'],
-      'category' => 'item_category',
-    ]);
-    $entity_2->save();
-    $entity_3 = $entity_test_storage->create([
-      'name' => 'bar',
-      'body' => 'test foobar',
-      'type' => 'item',
-    ]);
-    $entity_3->save();
-    $entity_4 = $entity_test_storage->create([
-      'name' => 'foo baz',
-      'body' => 'test test test',
-      'type' => 'article',
-      'keywords' => ['apple', 'strawberry', 'grape'],
-      'category' => 'article_category',
-    ]);
-    $entity_4->save();
-    $entity_5 = $entity_test_storage->create([
-      'name' => 'bar baz',
-      'body' => 'foo',
-      'type' => 'article',
-      'keywords' => ['orange', 'strawberry', 'grape', 'banana'],
-      'category' => 'article_category',
-    ]);
-    $entity_5->save();
-
-    $inserted_entities = \Drupal::entityQuery('entity_test_mulrev_changed')
-      ->count()
-      ->execute();
-    $this->assertEquals(5, $inserted_entities, "5 items inserted.");
-
-    /** @var \Drupal\search_api\IndexInterface $index */
-    $index = Index::load('database_search_index');
-    $indexed_items = $index->indexItems();
-    $this->assertEquals(5, $indexed_items, '5 items indexed.');
-  }
-
-  /**
-   * Create and place a facet block in the first sidebar.
-   *
-   * @param string $id
-   *   Create a block for a facet.
-   */
-  protected function createBlock($id) {
-    $config = \Drupal::configFactory();
-    $settings = [
-      'plugin' => 'facet_block:' . $id,
-      'region' => 'sidebar_first',
-      'id' => $id . '_block',
-      'theme' => $config->get('system.theme')->get('default'),
-      'label' => ucfirst($id) . ' block',
-      'visibility' => [],
-      'weight' => 0,
-    ];
-
-    foreach (['region', 'id', 'theme', 'plugin', 'weight', 'visibility'] as $key) {
-      $values[$key] = $settings[$key];
-      // Remove extra values that do not belong in the settings array.
-      unset($settings[$key]);
-    }
-    $values['settings'] = $settings;
-    $block = Block::create($values);
-    $block->save();
-  }
-
 }