diff --git a/core/lib/Drupal/Core/Entity/Annotation/FieldType.php b/core/lib/Drupal/Core/Entity/Annotation/FieldType.php
index 0ab92a7..6934677 100644
--- a/core/lib/Drupal/Core/Entity/Annotation/FieldType.php
+++ b/core/lib/Drupal/Core/Entity/Annotation/FieldType.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\Core\Entity\Annotation;
 
-use Drupal\Component\Annotation\Plugin;
 use Drupal\Core\TypedData\Annotation\DataType;
 
 /**
diff --git a/core/lib/Drupal/Core/Entity/Field/FieldTypePluginManager.php b/core/lib/Drupal/Core/Entity/Field/FieldTypePluginManager.php
index 78ba0e1..df1f19d 100644
--- a/core/lib/Drupal/Core/Entity/Field/FieldTypePluginManager.php
+++ b/core/lib/Drupal/Core/Entity/Field/FieldTypePluginManager.php
@@ -107,11 +107,7 @@ public function getDefaultInstanceSettings($type) {
    *   An array of field type definitions.
    */
   public function getDefinitions($configurable = FALSE) {
-    $definitions = $this->getCachedDefinitions();
-    if (!isset($definitions)) {
-      $definitions = $this->findDefinitions();
-      $this->setCachedDefinitions($definitions);
-    }
+    $definitions = parent::getDefinitions();
     if ($configurable) {
       return array_filter($this->definitions, function ($definition) {
         return $definition['configurable'];
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/BooleanItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/BooleanItem.php
index e60cdd4..b0d9427 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/BooleanItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/BooleanItem.php
@@ -16,7 +16,7 @@
  *   id = "boolean",
  *   label = @Translation("Boolean"),
  *   description = @Translation("An entity field containing a boolean value."),
- *   configurable = false
+ *   configurable = FALSE
  * )
  */
 class BooleanItem extends FieldItemBase {
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/DateItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/DateItem.php
index 5245abb..96a0791 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/DateItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/DateItem.php
@@ -16,7 +16,7 @@
  *   id = "date",
  *   label = @Translation("Date"),
  *   description = @Translation("An entity field containing a date value."),
- *   configurable = false
+ *   configurable = FALSE
  * )
  */
 class DateItem extends FieldItemBase {
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/EntityReferenceItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/EntityReferenceItem.php
index 4891b5e..5e37050 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/EntityReferenceItem.php
@@ -25,7 +25,7 @@
  *   id = "entity_reference",
  *   label = @Translation("Entity reference"),
  *   description = @Translation("An entity field containing an entity reference."),
- *   configurable = false,
+ *   configurable = FALSE,
  *   constraints = {"ValidReference" = TRUE}
  * )
  */
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/FloatItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/FloatItem.php
index ce571e8..1dc4713 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/FloatItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/FloatItem.php
@@ -16,7 +16,7 @@
  *   id = "float",
  *   label = @Translation("Float"),
  *   description = @Translation("An entity field containing an float value."),
- *   configurable = false
+ *   configurable = FALSE
  * )
  */
 class FloatItem extends FieldItemBase {
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/IntegerItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/IntegerItem.php
index 5142dfc..e42ac21 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/IntegerItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/IntegerItem.php
@@ -16,7 +16,7 @@
  *   id = "integer",
  *   label = @Translation("Integer"),
  *   description = @Translation("An entity field containing an integer value."),
- *   configurable = false
+ *   configurable = FALSE
  * )
  */
 class IntegerItem extends FieldItemBase {
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/LanguageItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/LanguageItem.php
index e0ec10b..17eabdb 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/LanguageItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/LanguageItem.php
@@ -17,7 +17,7 @@
  *   id = "language",
  *   label = @Translation("Language"),
  *   description = @Translation("An entity field referencing a language."),
- *   configurable = false,
+ *   configurable = FALSE,
  *   constraints = {
  *     "ComplexData" = {
  *       "value" = {"Length" = {"max" = 12}}
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/StringItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/StringItem.php
index a0008a9..1e5237c 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/StringItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/StringItem.php
@@ -16,7 +16,7 @@
  *   id = "string",
  *   label = @Translation("String"),
  *   description = @Translation("An entity field containing a string value."),
- *   configurable = false
+ *   configurable = FALSE
  * )
  */
 class StringItem extends FieldItemBase {
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UriItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UriItem.php
index 2a268c8..9c1cabd 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UriItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UriItem.php
@@ -16,7 +16,7 @@
  *   id = "uri",
  *   label = @Translation("URI"),
  *   description = @Translation("An entity field containing a URI."),
- *   configurable = false
+ *   configurable = FALSE
  * )
  */
 class UriItem extends FieldItemBase {
diff --git a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UuidItem.php b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UuidItem.php
index 5e3e8e7..2b3d6ea 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UuidItem.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/field/field_type/UuidItem.php
@@ -16,7 +16,7 @@
  *   id = "uuid",
  *   label = @Translation("UUID"),
  *   description = @Translation("An entity field containing a UUID."),
- *   configurable = false,
+ *   configurable = FALSE,
  *   constraints = {
  *     "ComplexData" = {
  *       "value" = {"Length" = {"max" = 128}}
diff --git a/core/modules/path/lib/Drupal/path/Plugin/field/field_type/PathItem.php b/core/modules/path/lib/Drupal/path/Plugin/field/field_type/PathItem.php
index e796bd0..db9b4f5 100644
--- a/core/modules/path/lib/Drupal/path/Plugin/field/field_type/PathItem.php
+++ b/core/modules/path/lib/Drupal/path/Plugin/field/field_type/PathItem.php
@@ -16,7 +16,7 @@
  *   id = "path",
  *   label = @Translation("Path"),
  *   description = @Translation("An entity field containing a path alias and related data."),
- *   configurable = false
+ *   configurable = FALSE
  * )
  */
 class PathItem extends FieldItemBase {