diff --git a/src/TranslatorPluginUiBase.php b/src/TranslatorPluginUiBase.php
index 2dd6359..0ef7a29 100644
--- a/src/TranslatorPluginUiBase.php
+++ b/src/TranslatorPluginUiBase.php
@@ -105,7 +105,7 @@ class TranslatorPluginUiBase extends ComponentPluginBase implements TranslatorPl
   public function submitTestCredentials(array $form, FormStateInterface $form_state) {
     // When this method is called the form already passed validation and we can
     // assume that credentials are valid.
-    drupal_set_message('Valid credentials');
+    drupal_set_message(t('Valid credentials'));
     $form_state->setRebuild();
   }