diff --git a/classes/grades/synchronization/xapi_request.php b/classes/grades/synchronization/xapi_request.php
index 666e1fc..f5185d4 100644
--- a/classes/grades/synchronization/xapi_request.php
+++ b/classes/grades/synchronization/xapi_request.php
@@ -75,10 +75,10 @@ private function has_error(array $response): bool {
      * @return mixed curl handle for json payload
      */
     public function create_post_curl_request() {
-        $post_fields= json_encode($this->payload);
+        $postfields = json_encode($this->payload);
         $ch = curl_init($this->server->get_grade_sync_url());
         curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
-        curl_setopt($ch, CURLOPT_POSTFIELDS, $post_fields);
+        curl_setopt($ch, CURLOPT_POSTFIELDS, $postfields);
         curl_setopt($ch, CURLOPT_USERAGENT, "My User Agent Name");
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
         curl_setopt(
@@ -86,7 +86,7 @@ public function create_post_curl_request() {
             CURLOPT_HTTPHEADER,
             array(
                 'Content-Type: application/json',
-                'Content-Length: ' . strlen($post_fields),
+                'Content-Length: ' . strlen($postfields),
                 "X-API-Key: " . get_config('auth_mumie', 'mumie_api_key'),
             )
         );
diff --git a/gradesync.php b/gradesync.php
index 3d72926..cc090f7 100644
--- a/gradesync.php
+++ b/gradesync.php
@@ -189,8 +189,8 @@ public static function get_all_grades_for_user(stdClass $mumie, int $userid) : ?
      */
     private static function xapi_to_moodle_grade($xapigrade) : stdClass {
         $grade = new stdClass();
-        $sync_id = self::get_mumie_user_from_sync_id($xapigrade->actor->account->name);
-        $grade->userid = $sync_id->get_moodle_id();
+        $syncid = self::get_mumie_user_from_sync_id($xapigrade->actor->account->name);
+        $grade->userid = $syncid->get_moodle_id();
         $grade->rawgrade = 100 * $xapigrade->result->score->raw;
         $grade->timecreated = strtotime($xapigrade->timestamp);
         return $grade;