diff --git a/calendar/teachingdates/app.py b/calendar/teachingdates/app.py
index bb4e012..3f0cb8b 100644
--- a/calendar/teachingdates/app.py
+++ b/calendar/teachingdates/app.py
@@ -24,8 +24,10 @@
                 prog=PROG, c=dates_config.get_paper_config()))
         cal = calendars.TeachingCalendar(dates_config)
         if args.debug:
-            print("Calendar: {cal}".format(cal=cal.calendar()))
-            print("Lectures: {lec}".format(lec=cal.lecture_dates()))
+            print("Calendars: {cal}".format(cal=cal.calendars))
+            print("{cls}: {dates}".format(
+                cls=dates_config.style.title() + "s",
+                dates=cal.class_dates()))
         print(cal.render(args.style, args.format))
 
     except configuration.ConfigurationError as e: