diff --git a/mycaldav/models.py b/mycaldav/models.py
index 6ce8661..87ab069 100644
--- a/mycaldav/models.py
+++ b/mycaldav/models.py
@@ -186,13 +186,20 @@ class cls_caldav_client():
          #   print(event.vobject_instance.vevent.eventId)
     def mark_as_done_task(self,calandar,uuid):
         event = self.get_event_by_uuid(calandar=calandar,uuid=uuid)
-        if "#Fait" not in event.vobject_instance.vevent.description.value:
-            event.vobject_instance.vevent.description.value = event.vobject_instance.vevent.description.value + " #Fait"
-        else:
-            while "#Fait#Fait" in event.vobject_instance.vevent.description.value:
-                event.vobject_instance.vevent.description.value = event.vobject_instance.vevent.description.value.replace("#Fait#Fait","#Fait")
 
-        event.save()
+        try:
+            _desc = event.vobject_instance.vevent.description.value + "#Fait"
+            _desc.replace("#Fait#Fait","#Fait")
+        except AttributeError:
+            _desc = "#Fait"
+
+        my_event = calandar.save_event(
+            dtstart=event.vobject_instance.vevent.dtstart.value,
+            dtend=event.vobject_instance.vevent.dtend.value,
+            summary=event.vobject_instance.vevent.summary.value,
+            description=_desc,
+        )
+        event.delete()