diff --git a/src/BusProNet/DataProcessor/PersonalDataSynchronizer.php b/src/BusProNet/DataProcessor/PersonalDataSynchronizer.php
index fde530f..f7b00ba 100644
--- a/src/BusProNet/DataProcessor/PersonalDataSynchronizer.php
+++ b/src/BusProNet/DataProcessor/PersonalDataSynchronizer.php
@@ -41,8 +41,10 @@ class PersonalDataSynchronizer
         $this->fillMissingApplicantFields($bookingData);
 
         foreach ($participants as $participant) {
-            // Skip canceled participants (status 'S')
+            // For canceled participants, only ensure mandatory fields have defaults
+            // Skip other field updates as their data cannot be edited
             if ('S' === $participant->status) {
+                $this->fillMissingParticipantFields($bookingData->participants[$participant->index]);
                 continue;
             }