diff --git a/better_exposed_filters.theme b/better_exposed_filters.theme
index d51a79d..0bf6491 100644
--- a/better_exposed_filters.theme
+++ b/better_exposed_filters.theme
@@ -49,7 +49,7 @@ function theme_select_as_checkboxes_details($vars) {
   $children = '';
   if (!empty($element['#bef_operator'])) {
     // Put an exposed operator inside the details element.
-    $children = drupal_render($element['#bef_operator']);
+    $children = Drupal::service('renderer')->render($element['#bef_operator']);
   }
 
   // Render the checkboxes.
@@ -174,7 +174,7 @@ function theme_select_as_radios_details($vars) {
   $children = '';
   if (!empty($element['#bef_operator'])) {
     // Put an exposed operator inside the fieldset.
-    $children = drupal_render($element['#bef_operator']);
+    $children = Drupal::service('renderer')->render($element['#bef_operator']);
   }
 
   // Render the radio buttons.
@@ -478,7 +478,7 @@ function theme_secondary_exposed_elements($vars) {
   // TODO: put HTML in a template
   $output = '<div class="bef-secondary-options">';
   foreach (element_children($element) as $id) {
-    $output .= drupal_render($element[$id]);
+    $output .= Drupal::service('renderer')->render($element[$id]);
   }
   $output .= '</div>';