diff --git a/caldav/objects.py b/caldav/objects.py
index 5cf7314..0e78b0b 100644
--- a/caldav/objects.py
+++ b/caldav/objects.py
@@ -2999,7 +2999,7 @@ def complete(
            * safe - see doc for _complete_recurring_safe for details
         """
         if not completion_timestamp:
-            completion_timestamp = datetime.utcnow().astimezone(timezone.utc)
+            completion_timestamp = datetime.now(timezone.utc)
 
         if "RRULE" in self.icalendar_component and handle_rrule:
             return getattr(self, "_complete_recurring_%s" % rrule_mode)(
diff --git a/tests/test_caldav.py b/tests/test_caldav.py
index d7e5e0e..1fd855d 100644
--- a/tests/test_caldav.py
+++ b/tests/test_caldav.py
@@ -2288,7 +2288,7 @@ def testCreateOverwriteDeleteEvent(self):
         if not self.check_compatibility_flag(
             "no_todo"
         ) and not self.check_compatibility_flag("no_todo_on_standard_calendar"):
-            t1.delete
+            t1.delete()
 
         if self.check_compatibility_flag("non_existing_raises_other"):
             expected_error = error.DAVError