diff --git a/mollom.module b/mollom.module
index 1ac0d66..301bdae 100644
--- a/mollom.module
+++ b/mollom.module
@@ -300,7 +300,7 @@ function mollom_form_alter(&$form, FormStateInterface $form_state, $form_id) {
   $base_form_id = isset($build_info['base_form_id']) ? $build_info['base_form_id'] : $form_id;
   $protected_form_id = '';
   if (isset($forms['protected'][$form_id])) {
-    $protected_form_id = [$form_id];
+    $protected_form_id = $form_id;
   }
   else if (isset($forms['protected'][$base_form_id])) {
     $protected_form_id = $base_form_id;