diff -u b/core/modules/system/src/Tests/Entity/ValidReferenceConstraintValidatorTest.php b/core/modules/system/src/Tests/Entity/ValidReferenceConstraintValidatorTest.php
--- b/core/modules/system/src/Tests/Entity/ValidReferenceConstraintValidatorTest.php
+++ b/core/modules/system/src/Tests/Entity/ValidReferenceConstraintValidatorTest.php
@@ -55,13 +55,13 @@
     // NULL is also considered a valid reference.
     $typed_data = $this->typedData->create($definition, array('target_id' => NULL));
     $violations = $typed_data->validate();
-    $this->assertEqual($violations->count(), 0, 'Validation passed for correct value.');
+    $this->assertFalse($violations->count(), 'Validation passed for correct value.');
 
     $typed_data = $this->typedData->create($definition, array('target_id' => $entity->id()));
     // Delete the referenced entity.
     $entity->delete();
     $violations = $typed_data->validate();
-    $this->assertEqual($violations->count(), 1, 'Validation failed for incorrect value.');
+    $this->assertTrue($violations->count(), 'Validation failed for incorrect value.');
 
     // Make sure the information provided by a violation is correct.
     $violation = $violations[0];