diff --git a/src/Form/PermissionsLockForm.php b/src/Form/PermissionsLockForm.php
index 3b5503b..7aeffd8 100644
--- a/src/Form/PermissionsLockForm.php
+++ b/src/Form/PermissionsLockForm.php
@@ -105,7 +105,7 @@ class PermissionsLockForm extends ConfigFormBase {
     }
     $form['permissions_lock_roles'] = array(
       '#type' => 'fieldset',
-      '#title' => t('Roles'),
+      '#title' => $this->t('Roles'),
       '#weight' => 0,
       '#collapsible' => TRUE,
     );
@@ -113,8 +113,8 @@ class PermissionsLockForm extends ConfigFormBase {
     //$hook_lock_roles = permissions_lock_get_hook_data('role');
     $form['permissions_lock_roles']['permissions_lock_locked_roles'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Locked roles'),
-      '#description' => t("Users without the 'manage permissions unrestricted' permission will not be able to change permissions for the selected roles."),
+      '#title' => $this->t('Locked roles'),
+      '#description' => $this->t("Users without the 'manage permissions unrestricted' permission will not be able to change permissions for the selected roles."),
       "#default_value" => $default_roles,
       '#options' => user_role_names(),
       // '#options' => array(t('UK'), t('Other')),
@@ -126,15 +126,15 @@ class PermissionsLockForm extends ConfigFormBase {
 
     $form['permissions_lock_permissions'] = array(
       '#type' => 'fieldset',
-      '#title' => t('Permissions'),
+      '#title' => $this->t('Permissions'),
       '#weight' => 0,
       '#collapsible' => TRUE,
       '#collapsed' => TRUE,
     );
     $form['permissions_lock_permissions']['permissions_lock_locked_perm'] = array(
       '#type' => 'checkboxes',
-      '#title' => t('Locked permissions'),
-      '#description' => t("Specify which permissions will not be changeable by users without the 'manage permissions unrestricted' permission"),
+      '#title' => $this->t('Locked permissions'),
+      '#description' => $this->t("Specify which permissions will not be changeable by users without the 'manage permissions unrestricted' permission"),
       "#default_value" => $default_perms,
       '#options' => $permissions,
       // '#options' => array(t('UK'), t('Other')),
@@ -148,7 +148,7 @@ class PermissionsLockForm extends ConfigFormBase {
 
     $form['submit'] = array(
       '#type' => 'submit',
-      '#value' => t('Save'),
+      '#value' => $this->t('Save'),
       '#weight' => 15,
     );
     return $form;
diff --git a/src/Tests/PermissionsLockUnrestrictedTestCase.php b/src/Tests/PermissionsLockUnrestrictedTestCase.php
index 2715712..e2c28ed 100644
--- a/src/Tests/PermissionsLockUnrestrictedTestCase.php
+++ b/src/Tests/PermissionsLockUnrestrictedTestCase.php
@@ -47,7 +47,7 @@ class PermissionsLockUnrestrictedTestCase extends WebTestBase {
     $this->drupalGet('admin/people/permissions');
 
     // make sure we are on the administration page
-    $this->assertResponse(200, t('User has access to the administration page'));
+    $this->assertResponse(200, $this->t('User has access to the administration page'));
 
     // check if the defined permissions are locked
     $this->assertText(t('Use the site in maintenance mode'));
@@ -58,7 +58,7 @@ class PermissionsLockUnrestrictedTestCase extends WebTestBase {
     $this->drupalGet('admin/people/permissions');
 
     // make sure we are on the administration page
-    $this->assertResponse(200, t('User has access to the administration page'));
+    $this->assertResponse(200, $this->t('User has access to the administration page'));
 
     // check if the defined permissions are locked
     $this->assertText(t('authenticated user'));