diff --git a/core/modules/field/field.info.inc b/core/modules/field/field.info.inc
index 79345a84efa34af5ca4ac1f165738a15fcd4be00..3c6bfde97c5a8221c36931912e71785d2a417842 100644
--- a/core/modules/field/field.info.inc
+++ b/core/modules/field/field.info.inc
@@ -44,29 +44,6 @@ function field_info_cache_clear() {
   Field::fieldInfo()->flush();
 }
 
-/**
- * Determines the behavior of a widget with respect to an operation.
- *
- * @param string $op
- *   The name of the operation. Currently supported: 'default_value',
- *   'multiple_values'.
- * @param array $instance
- *   The field instance array.
- *
- * @return int
- *   One of these values:
- *   - FIELD_BEHAVIOR_NONE: Do nothing for this operation.
- *   - FIELD_BEHAVIOR_CUSTOM: Use the widget's callback function.
- *   - FIELD_BEHAVIOR_DEFAULT: Use field.module default behavior.
- */
-function field_behaviors_widget($op, $instance) {
-  $info = array();
-  if ($component = entity_get_form_display($instance['entity_type'], $instance['bundle'], 'default')->getComponent($instance['field_name'])) {
-    $info = \Drupal::service('plugin.manager.field.widget')->getDefinition($component['type']);
-  }
-  return isset($info[$op]) ? $info[$op] : FIELD_BEHAVIOR_DEFAULT;
-}
-
 /**
  * Returns all field definitions.
  *
diff --git a/core/modules/field/lib/Drupal/field/FieldInfo.php b/core/modules/field/lib/Drupal/field/FieldInfo.php
index e6411c3807147f48456b877049983b5bf72ace80..4113239020dd4422c91e5df401984ed18f4a2368 100644
--- a/core/modules/field/lib/Drupal/field/FieldInfo.php
+++ b/core/modules/field/lib/Drupal/field/FieldInfo.php
@@ -588,11 +588,6 @@ public function prepareInstance($instance, $field_type) {
     // Make sure all expected instance settings are present.
     $instance['settings'] += $this->fieldTypeManager->getDefaultInstanceSettings($field_type);
 
-    // Set a default value for the instance.
-    if (field_behaviors_widget('default value', $instance) == FIELD_BEHAVIOR_DEFAULT && !isset($instance['default_value'])) {
-      $instance['default_value'] = NULL;
-    }
-
     return $instance;
   }