diff --git a/tests/src/Functional/CaptchaPersistenceTest.php b/tests/src/Functional/CaptchaPersistenceTest.php
index 7529ff7..e8e5274 100755
--- a/tests/src/Functional/CaptchaPersistenceTest.php
+++ b/tests/src/Functional/CaptchaPersistenceTest.php
@@ -78,7 +78,7 @@ class CaptchaPersistenceTest extends CaptchaWebTestBase {
       'pass' => 'bazlaz',
       'captcha_response' => 'Test 123',
     ];
-    $this->drupalPostForm(NULL, $edit, t('Log in'), [], self::LOGIN_HTML_FORM_ID);
+    $this->drupalPostForm(NULL, $edit, $this->t('Log in'), [], self::LOGIN_HTML_FORM_ID);
     // Check that there was no error message for the CAPTCHA.
     $this->assertCaptchaResponseAccepted();
 
@@ -88,7 +88,7 @@ class CaptchaPersistenceTest extends CaptchaWebTestBase {
     $this->assertPreservedCsid($captcha_sid_initial);
 
     // Post from again.
-    $this->drupalPostForm(NULL, $edit, t('Log in'), [], self::LOGIN_HTML_FORM_ID);
+    $this->drupalPostForm(NULL, $edit, $this->t('Log in'), [], self::LOGIN_HTML_FORM_ID);
     // Check that there was no error message for the CAPTCHA.
     $this->assertCaptchaResponseAccepted();
     $this->assertPreservedCsid($captcha_sid_initial);
@@ -112,7 +112,7 @@ class CaptchaPersistenceTest extends CaptchaWebTestBase {
       'pass' => 'bazlaz',
       'captcha_response' => 'Test 123',
     ];
-    $this->drupalPostForm(NULL, $edit, t('Log in'), [], self::LOGIN_HTML_FORM_ID);
+    $this->drupalPostForm(NULL, $edit, $this->t('Log in'), [], self::LOGIN_HTML_FORM_ID);
     // Check that there was no error message for the CAPTCHA.
     $this->assertCaptchaResponseAccepted();
     // There shouldn't be a CAPTCHA on the new form.
@@ -149,7 +149,7 @@ class CaptchaPersistenceTest extends CaptchaWebTestBase {
       'pass' => 'bazlaz',
       'captcha_response' => 'Test 123',
     ];
-    $this->drupalPostForm(NULL, $edit, t('Log in'), [], self::LOGIN_HTML_FORM_ID);
+    $this->drupalPostForm(NULL, $edit, $this->t('Log in'), [], self::LOGIN_HTML_FORM_ID);
     // Check that there was no error message for the CAPTCHA.
     $this->assertCaptchaResponseAccepted();
     // There shouldn't be a CAPTCHA on the new form.
@@ -191,7 +191,7 @@ class CaptchaPersistenceTest extends CaptchaWebTestBase {
       'pass' => 'bazlaz',
       'captcha_response' => 'Test 123',
     ];
-    $this->drupalPostForm(NULL, $edit, t('Log in'), [], self::LOGIN_HTML_FORM_ID);
+    $this->drupalPostForm(NULL, $edit, $this->t('Log in'), [], self::LOGIN_HTML_FORM_ID);
     // Check that there was no error message for the CAPTCHA.
     $this->assertCaptchaResponseAccepted();
     // There shouldn't be a CAPTCHA on the new form.
diff --git a/tests/src/Functional/CaptchaWebTestBase.php b/tests/src/Functional/CaptchaWebTestBase.php
index ba69163..9727016 100755
--- a/tests/src/Functional/CaptchaWebTestBase.php
+++ b/tests/src/Functional/CaptchaWebTestBase.php
@@ -7,6 +7,7 @@ use Drupal\comment\Tests\CommentTestTrait;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\Tests\BrowserTestBase;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
 
 /**
  * Base class for CAPTCHA tests.
@@ -16,6 +17,7 @@ use Drupal\Tests\BrowserTestBase;
 abstract class CaptchaWebTestBase extends BrowserTestBase {
 
   use CommentTestTrait;
+  use StringTranslationTrait;
 
   /**
    * Wrong response error message.