--- /dev/null
+<?php
+
+/**
+ * @file
+ * Handles Advanced Aggregation mod submodule installation and upgrade tasks.
+ */
+
+/**
+ * Implements hook_update_N().
+ *
+ * Set the css_defer_admin setting value.
+ */
+function advagg_mod_update_8201() {
+ \Drupal::service('config.factory')
+ ->getEditable('advagg_mod.settings')
+ ->set('css_defer_admin', FALSE)
+ ->save();
+}