diff --git a/src/program/signal_handlers.py b/src/program/signal_handlers.py
index 0941b8bd..98685b46 100644
--- a/src/program/signal_handlers.py
+++ b/src/program/signal_handlers.py
@@ -1,15 +1,15 @@
 from django.core.exceptions import ValidationError
 
 
-def check_speaker_event_camp_consistency(sender, event, **kwargs):
+def check_speaker_event_camp_consistency(sender, instance, **kwargs):
     if kwargs['action'] == 'pre_add':
         # loop over speakers being added to this event
         for pk in kwargs['pk_set']:
             # check if this speaker belongs to a different event than the event does
             from program.models import Speaker
             speaker = Speaker.objects.get(id=pk)
-            if speaker.camp != event.camp:
-                raise ValidationError({'speakers': 'The speaker (%s) belongs to a different camp (%s) than the event does (%s)' % (speaker, speaker.camp, event.camp)})
+            if speaker.camp != instance.camp:
+                raise ValidationError({'speakers': 'The speaker (%s) belongs to a different camp (%s) than the event does (%s)' % (speaker, speaker.camp, instance.camp)})
 
 
 def check_speaker_camp_change(sender, instance, **kwargs):