diff -u b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
--- b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
@@ -166,10 +166,9 @@
    */
   public function entityDefinitionIsInternalProvider() {
     return [
-      [TRUE, TRUE],
-      [FALSE, FALSE],
-      // Test entity types which have not defined a value for 'internal'.
-      [NULL, FALSE],
+      'internal' => [TRUE, TRUE],
+      'external' => [FALSE, FALSE],
+      'undefined' => [NULL, FALSE],
     ];
   }