diff --git a/calendar/teachingdates/app.py b/calendar/teachingdates/app.py
index b5ae874..45f8565 100644
--- a/calendar/teachingdates/app.py
+++ b/calendar/teachingdates/app.py
@@ -20,11 +20,7 @@
                 prog=PROG, c=dates_config.get_period_config()))
             print("{prog}: debug: paper config: {c}".format(
                 prog=PROG, c=dates_config.get_paper_config()))
-        cal = calendars.TeachingCalendar(dates_config.year,
-                                         dates_config.period,
-                                         dates_config.paper,
-                                         dates_config.get_period_config(),
-                                         dates_config.get_paper_config())
+        cal = calendars.TeachingCalendar.from_configuration(dates_config)
         print("Period = {p}".format(p=args.period))
         print(cal.calendar())
         print(cal.lecture_dates())