diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
index 0c857ad..669670d 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
@@ -328,4 +328,16 @@ function testSettingsInfo() {
       $this->assertIdentical(field_info_formatter_settings($type), $info['settings'], format_string("field_info_formatter_settings returns %type's formatter settings", array('%type' => $type)));
     }
   }
+
+  /**
+   * Test that the widget definition functions work.
+   */
+  function testWidgetDefinition() {
+
+    $widget_definition = field_get_plugin_manager('widget')->getDefinition('test_field_widget_multiple');
+
+    // Test if hook_field_widget_info_alter is beïng called.
+    $this->assertTrue(in_array('test_field', $widget_definition['field_types']), 'hook_field_widget_info_alter is beïng called');
+
+  }
 }
diff --git a/core/modules/field/tests/modules/field_test/field_test.field.inc b/core/modules/field/tests/modules/field_test/field_test.field.inc
index f47ccad..0674260 100644
--- a/core/modules/field/tests/modules/field_test/field_test.field.inc
+++ b/core/modules/field/tests/modules/field_test/field_test.field.inc
@@ -48,6 +48,13 @@ function field_test_field_info() {
 }
 
 /**
+ * Implements hook_field_widget_info_alter().
+ */
+function field_test_field_widget_info_alter(&$info) {
+  $info['test_field_widget_multiple']['field_types'][] = 'test_field';
+}
+
+/**
  * Implements hook_field_update_forbid().
  */
 function field_test_field_update_forbid($field, $prior_field, $has_data) {
diff --git a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/field/widget/TestFieldWidgetMultiple.php b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/field/widget/TestFieldWidgetMultiple.php
index ead51bd..32655da 100644
--- a/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/field/widget/TestFieldWidgetMultiple.php
+++ b/core/modules/field/tests/modules/field_test/lib/Drupal/field_test/Plugin/field/widget/TestFieldWidgetMultiple.php
@@ -18,9 +18,6 @@
  *   id = "test_field_widget_multiple",
  *   module = "field_test",
  *   label = @Translation("Test widget - multiple"),
- *   field_types = {
- *      "test_field"
- *   },
  *   settings = {
  *     "test_widget_setting_multiple" = "dummy test string"
  *   },