diff --git a/core/modules/block/tests/lib/Drupal/block/Tests/BlockFormControllerTest.php b/core/modules/block/tests/lib/Drupal/block/Tests/BlockFormControllerTest.php
index 8b40333..c1677c5 100644
--- a/core/modules/block/tests/lib/Drupal/block/Tests/BlockFormControllerTest.php
+++ b/core/modules/block/tests/lib/Drupal/block/Tests/BlockFormControllerTest.php
@@ -78,7 +78,11 @@ public function testGetUniqueMachineName() {
       ->method('getStorageController')
       ->will($this->returnValue($block_storage));
 
-    $block_form_controller = new BlockFormController($entity_manager, $query_factory);
+    $language_manager = $this->getMockBuilder('Drupal\Core\Language\LanguageManager')
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $block_form_controller = new BlockFormController($entity_manager, $query_factory, $language_manager);
 
     // Ensure that the block with just one other instance gets the next available
     // name suggestion.