diff --git a/core/modules/field/field.post_update.php b/core/modules/field/field.post_update.php
index faa6a69..4c2e74d 100644
--- a/core/modules/field/field.post_update.php
+++ b/core/modules/field/field.post_update.php
@@ -5,6 +5,7 @@
  * Post update functions for Field module.
  */
 
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\field\Entity\FieldConfig;
 
@@ -42,5 +43,27 @@ function field_post_update_entity_reference_handler_setting() {
 }
 
 /**
+ * Adds the 'size' setting for email fields.
+ */
+function field_post_update_email_widget_size_setting() {
+  foreach (EntityFormDisplay::loadMultiple() as $entity_form_display) {
+    $changed = FALSE;
+    foreach ($entity_form_display->getComponents() as $name => $options) {
+      if ($options['type'] == 'email_default') {
+        $options['settings']['size'] = '60';
+        $entity_form_display->setComponent($name, $options);
+        $changed = TRUE;
+      }
+    }
+
+    if ($changed) {
+      $entity_form_display->save();
+    }
+  }
+
+  return t('The new size setting for email fields has been added.');
+}
+
+/**
  * @} End of "addtogroup updates-8.0.0-beta".
  */