diff --git a/src/Plugin/Block/FacetBlock.php b/src/Plugin/Block/FacetBlock.php
index 02599c8..e7dd781 100644
--- a/src/Plugin/Block/FacetBlock.php
+++ b/src/Plugin/Block/FacetBlock.php
@@ -94,6 +94,13 @@ class FacetBlock extends BlockBase implements ContainerFactoryPluginInterface {
         'route_parameters' => ['facets_facet' => $facet->id()],
       ];
 
+      if (in_array('facet-active', $build[0]['#attributes']['class'], TRUE)) {
+        $build['#attributes']['class'][] = 'facet-active';
+      }
+      else {
+        $build['#attributes']['class'][] = 'facet-inactive';
+      }
+
       // Add classes needed for ajax.
       if (!empty($build['#use_ajax'])) {
         $build['#attributes']['class'][] = 'block-facets-ajax';
diff --git a/src/Widget/WidgetPluginBase.php b/src/Widget/WidgetPluginBase.php
index bd0987f..45b896f 100644
--- a/src/Widget/WidgetPluginBase.php
+++ b/src/Widget/WidgetPluginBase.php
@@ -77,6 +77,7 @@ abstract class WidgetPluginBase extends PluginBase implements WidgetPluginInterf
       '#attributes' => [
         'data-drupal-facet-id' => $facet->id(),
         'data-drupal-facet-alias' => $facet->getUrlAlias(),
+        'class' => [$facet->getActiveItems() ? 'facet-active' : 'facet-inactive'],
       ],
       '#context' => ['list_style' => $widget['type']],
       '#cache' => [
diff --git a/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php b/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php
index d182688..e606718 100644
--- a/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php
+++ b/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php
@@ -32,7 +32,7 @@ class CheckboxWidgetTest extends WidgetTestBase {
     $this->assertInternalType('array', $output);
     $this->assertCount(4, $output['#items']);
 
-    $this->assertEquals(['js-facets-checkbox-links'], $output['#attributes']['class']);
+    $this->assertEquals(['facet-inactive', 'js-facets-checkbox-links'], $output['#attributes']['class']);
 
     $expected_links = [
       $this->buildLinkAssertion('Llama', 'llama', $facet, 10),
diff --git a/tests/src/Unit/Plugin/widget/DropdownWidgetTest.php b/tests/src/Unit/Plugin/widget/DropdownWidgetTest.php
index 76a126e..0e08ebb 100644
--- a/tests/src/Unit/Plugin/widget/DropdownWidgetTest.php
+++ b/tests/src/Unit/Plugin/widget/DropdownWidgetTest.php
@@ -33,7 +33,7 @@ class DropdownWidgetTest extends WidgetTestBase {
     $this->assertInternalType('array', $output);
     $this->assertCount(4, $output['#items']);
 
-    $this->assertEquals(['js-facets-dropdown-links'], $output['#attributes']['class']);
+    $this->assertEquals(['facet-inactive', 'js-facets-dropdown-links'], $output['#attributes']['class']);
 
     $expected_links = [
       $this->buildLinkAssertion('Llama', 'llama', $facet, 10),