diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/MapItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/MapItem.php
index 3e21dc1..4645b83 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/MapItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/MapItem.php
@@ -27,9 +27,8 @@ class MapItem extends FieldItemBase {
    * {@inheritdoc}
    */
   public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
-    // The properties are dynamic and can not be defined statically. However, we
-    // allow setting some definitions on the field definition if they are known.
-    return $field_definition->getSetting('property_definitions') ?: array();
+    // The properties are dynamic and can not be defined statically.
+    return array();
   }
 
   /**