diff --git a/symposion/schedule/forms.py b/symposion/schedule/forms.py
index 1ab7de0f..286b2b63 100644
--- a/symposion/schedule/forms.py
+++ b/symposion/schedule/forms.py
@@ -8,4 +8,5 @@ class SlotEditForm(forms.Form):
     presentation = forms.ModelChoiceField(
         queryset=Presentation.objects.filter(slot__isnull=True),
         required=True,
+        empty_label=None,
     )