diff --git a/core/modules/field/src/Entity/FieldInstanceConfig.php b/core/modules/field/src/Entity/FieldInstanceConfig.php
index acf4ee8..5c757db 100644
--- a/core/modules/field/src/Entity/FieldInstanceConfig.php
+++ b/core/modules/field/src/Entity/FieldInstanceConfig.php
@@ -297,21 +297,13 @@ public function getType() {
   /**
    * {@inheritdoc}
    */
-  public function toArray() {
-    // Make sure the denormalized field_type property is populated and saved in
-    // the config records.
-    $this->getType();
-
-    return parent::toArray();
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function postCreate(EntityStorageInterface $storage) {
     // Validate that we have a valid storage for this instance. This throws an
     // exception if the storage is invalid.
     $this->getFieldStorageDefinition();
+    // Also, make sure the denormalized field_type property is populated and
+    // saved in the config records.
+    $this->getType();
 
     // 'Label' defaults to the field name (mostly useful for field instances
     // created in tests).