diff --git a/src/Plugin/EntityReferenceSelection/GroupTypeRoleSelection.php b/src/Plugin/EntityReferenceSelection/GroupTypeRoleSelection.php
index 0014f3e..2a8af9e 100644
--- a/src/Plugin/EntityReferenceSelection/GroupTypeRoleSelection.php
+++ b/src/Plugin/EntityReferenceSelection/GroupTypeRoleSelection.php
@@ -3,62 +3,84 @@
 namespace Drupal\group\Plugin\EntityReferenceSelection;
 
 use Drupal\Core\Entity\Plugin\EntityReferenceSelection\DefaultSelection;
+use Drupal\Core\Entity\Query\QueryInterface;
 use Drupal\Core\Form\FormStateInterface;
 
 /**
  * Only shows the group roles which are available for a group type.
  *
- * The only handler setting is 'group_type_id', a required string that points
+ * The first handler setting is 'group_type_id', a required string that points
  * to the ID of the group type for which this handler will be run.
  *
+ * The second is 'include_internal_roles', optional boolean flag that defines
+ * whether to include internal group roles (Member, Outsider etc.) in the list.
+ * Defaults to 0 - internal roles are not included.
+ *
  * @EntityReferenceSelection(
  *   id = "group_type:group_role",
  *   label = @Translation("Group type role selection"),
  *   entity_types = {"group_role"},
  *   group = "group_type",
- *   weight = 0,
  *   base_plugin_label = @Translation("Group: Roles"),
+ *   weight = 0,
  * )
  */
 class GroupTypeRoleSelection extends DefaultSelection {
 
-  /**
-   * {@inheritdoc}
-   */
-  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+  public function buildConfigurationForm(array $form, FormStateInterface $form_state): array {
     $form = parent::buildConfigurationForm($form, $form_state);
-    // Autocreation is not supported.
+
+    // Auto-creation is not supported.
     unset($form['auto_create']);
+
     $group_types = $this->entityTypeManager->getStorage('group_type')->loadMultiple();
     $group_type_options = [];
+
     if ($group_types) {
       $group_type_options[''] = $this->t('-Select group type-');
+
       foreach ($group_types as $group_type_id => $group_type) {
         $group_type_options[$group_type_id] = $group_type->label();
       }
     }
+
     $form['group_type_id'] = [
       '#type' => 'select',
       '#title' => $this->t('Group types'),
       '#options' => $group_type_options,
       '#default_value' => $this->configuration['group_type_id'] ?? '',
       '#access' => count($group_type_options) > 1,
-      '#weight' => -1,
+      '#weight' => -2,
       '#required' => TRUE,
     ];
+
+    $form['include_internal_roles'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Include internal group roles'),
+      '#default_value' => $this->configuration['include_internal_roles'] ?? 0,
+      '#weight' => -1,
+    ];
+
     return $form;
   }
+
   /**
    * {@inheritdoc}
    */
-  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS') {
+  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS'): QueryInterface {
+
     $query = parent::buildEntityQuery($match, $match_operator);
+
     if (!empty($this->configuration['group_type_id'])) {
       $group_type_id = $this->configuration['group_type_id'];
       $query->condition('group_type', $group_type_id, '=');
       $query->sort('label');
     }
 
+    if (empty($this->configuration['include_internal_roles'])) {
+      $query->condition('internal', 0, '=');
+    }
+
     return $query;
   }