diff --git a/plugins/talks.py b/plugins/talks.py
index 0efe43f..f358f5c 100644
--- a/plugins/talks.py
+++ b/plugins/talks.py
@@ -128,6 +128,10 @@ def get_talk_data(talkname):
         logging.warn("Talk <{}> has no `room` field".format(talkname))
     if 'time' not in data or 'day' not in data:
         logging.warn("Talk <{}> has no `time` or `day`".format(talkname))
+        if 'time' in data:
+            del data['time']
+        if 'day' in data:
+            del data['day']
     if 'day' in data:
         data['day'] = get_global_data()['startdate'] + datetime.timedelta(days=data['day'])
     if 'time' in data and 'day' in data:
@@ -266,7 +270,7 @@ def talks_to_ics():
 
 
 def talk_to_ics(talk):
-    if 'time' not in talk:
+    if 'time' not in talk or 'duration' not in talk:
         return ''
     start = talk['time']
     end  = start + datetime.timedelta(minutes=talk['duration'])