diff --git a/modules/cms/models/ThemeData.php b/modules/cms/models/ThemeData.php
index 907887d7e8..b6ff9af8b4 100644
--- a/modules/cms/models/ThemeData.php
+++ b/modules/cms/models/ThemeData.php
@@ -52,6 +52,14 @@ class ThemeData extends Model
      */
     protected static $instances = [];
 
+    /**
+     * after the model is booted, bind to 'model.afterFetch' event
+     */
+    public function afterBoot()
+    {
+        $this->bindEvent('model.afterFetch', [$this, 'afterFetchHandler']);
+    }
+
     /**
      * Before saving the model, strip dynamic attributes applied from config.
      * @return void
@@ -109,18 +117,18 @@ public static function forTheme($theme)
      * on form field definitions.
      * @return void
      */
-    public function afterFetch()
+    protected function afterFetchHandler()
     {
         $data = (array) $this->data + $this->getDefaultValues();
 
-        /*
-         * Repeater form fields store arrays and must be jsonable.
-         */
         foreach ($this->getFormFields() as $id => $field) {
             if (!isset($field['type'])) {
                 continue;
             }
 
+            /*
+             * Repeater form fields store arrays and must be jsonable.
+             */
             if ($field['type'] === 'repeater') {
                 $this->jsonable[] = $id;
             }