diff --git a/src/Plugin/Field/FieldWidget/InlineEntityFormMultiple.php b/src/Plugin/Field/FieldWidget/InlineEntityFormMultiple.php
index 98aad8e..208c419 100644
--- a/src/Plugin/Field/FieldWidget/InlineEntityFormMultiple.php
+++ b/src/Plugin/Field/FieldWidget/InlineEntityFormMultiple.php
@@ -123,7 +123,7 @@ class InlineEntityFormMultiple extends InlineEntityFormBase implements Container
     $element['#element_validate'] =[[get_class($this), 'updateRowWeights']];
     // Add the required element marker & validation.
     if ($element['#required']) {
-      $element['#element_validate'][] = 'inline_entity_form_required_field';
+      $element['#element_validate'][] = [get_class($this), 'requiredField'];
     }
 
     $element['entities'] = array(
@@ -849,7 +849,7 @@ class InlineEntityFormMultiple extends InlineEntityFormBase implements Container
   /**
    * Updates entity weights based on their weights in the widget.
    */
-  public static function updateRowWights($element, FormStateInterface $form_state, $form) {
+  public static function updateRowWeights($element, FormStateInterface $form_state, $form) {
     $ief_id = $element['#ief_id'];
 
     // Loop over the submitted delta values and update the weight of the entities