diff --git a/guild/forms.py b/guild/forms.py
index 239812f..de55a61 100644
--- a/guild/forms.py
+++ b/guild/forms.py
@@ -9,4 +9,5 @@ class PlaySessionForm(forms.ModelForm):
         # set date wideget to type="date"
         widgets = {
             "date": forms.DateInput(attrs={"type": "date"}),
+            "characters": forms.CheckboxSelectMultiple(),
         }