diff --git a/core/lib/Drupal/Core/Field/FormatterPluginManager.php b/core/lib/Drupal/Core/Field/FormatterPluginManager.php
index c4df0f5f2fd8c65812d14eed857d0ee96e8a66a3..46305a5f2b9d735fead732b33ba5900d1a4e4f1c 100644
--- a/core/lib/Drupal/Core/Field/FormatterPluginManager.php
+++ b/core/lib/Drupal/Core/Field/FormatterPluginManager.php
@@ -90,8 +90,8 @@ public function createInstance($plugin_id, array $configuration = []) {
    *     - third_party_settings: (array) Settings provided by other extensions
    *       through hook_field_formatter_third_party_settings_form().
    *
-   * @return \Drupal\Core\Field\FormatterInterface|null
-   *   A formatter object or NULL when plugin is not found.
+   * @return \Drupal\Core\Field\FormatterInterface|false
+   *   A formatter object or FALSE when plugin is not found.
    */
   public function getInstance(array $options) {
     $configuration = $options['configuration'];
@@ -114,7 +114,7 @@ public function getInstance(array $options) {
       // Grab the default widget for the field type.
       $field_type_definition = $this->fieldTypeManager->getDefinition($field_type);
       if (empty($field_type_definition['default_formatter'])) {
-        return NULL;
+        return FALSE;
       }
       $plugin_id = $field_type_definition['default_formatter'];
     }
@@ -123,7 +123,7 @@ public function getInstance(array $options) {
       'field_definition' => $field_definition,
       'view_mode' => $options['view_mode'],
     ];
-    return $this->createInstance($plugin_id, $configuration);
+    return $this->createInstance($plugin_id, $configuration) ?? FALSE;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/WidgetPluginManager.php b/core/lib/Drupal/Core/Field/WidgetPluginManager.php
index e5afb21e5fcd8fb732ecb86606e14a29488382fb..a2366f322706acf7f7fb288480d1773cbaa13873 100644
--- a/core/lib/Drupal/Core/Field/WidgetPluginManager.php
+++ b/core/lib/Drupal/Core/Field/WidgetPluginManager.php
@@ -69,8 +69,8 @@ public function __construct(\Traversable $namespaces, CacheBackendInterface $cac
    *     - third_party_settings: (array) Settings provided by other extensions
    *       through hook_field_formatter_third_party_settings_form().
    *
-   * @return \Drupal\Core\Field\WidgetInterface|null
-   *   A Widget object or NULL when plugin is not found.
+   * @return \Drupal\Core\Field\WidgetInterface|false
+   *   A Widget object or FALSE when plugin is not found.
    */
   public function getInstance(array $options) {
     // Fill in defaults for missing properties.
@@ -99,7 +99,7 @@ public function getInstance(array $options) {
       // Grab the default widget for the field type.
       $field_type_definition = $this->fieldTypeManager->getDefinition($field_type);
       if (empty($field_type_definition['default_widget'])) {
-        return NULL;
+        return FALSE;
       }
       $plugin_id = $field_type_definition['default_widget'];
     }
@@ -107,7 +107,7 @@ public function getInstance(array $options) {
     $configuration += [
       'field_definition' => $field_definition,
     ];
-    return $this->createInstance($plugin_id, $configuration);
+    return $this->createInstance($plugin_id, $configuration) ?? FALSE;
   }
 
   /**