diff --git a/cfp/forms.py b/cfp/forms.py
index 0778295..291e095 100644
--- a/cfp/forms.py
+++ b/cfp/forms.py
@@ -364,16 +364,8 @@ class VolunteerForm(forms.ModelForm):
         fields = ['name', 'email', 'phone_number', 'sms_prefered', 'notes']
 
 
-class ParticipantWidget(ModelSelect2MultipleWidget):
-    model = Participant
-    search_fields = [ '%s__icontains' % field for field in ['name', 'email', 'twitter', 'linkedin', 'github',
-                                                            'website', 'facebook', 'mastodon', 'phone_number' ]]
-
-
-class TalkSpeakerForm(forms.ModelForm):
-    class Meta:
-        model = Talk
-        fields = ['speakers']
-        widgets = {
-            'speakers': ParticipantWidget(),
-        }
+def get_talk_speaker_form_class(site):
+    fields = ['name', 'email', 'twitter', 'linkedin', 'github', 'website', 'facebook', 'mastodon', 'phone_number']
+    widget = ModelSelect2MultipleWidget(model=Participant, queryset=Participant.objects.filter(site=site),
+                                        search_fields=['%s__icontains' % field for field in fields])
+    return modelform_factory(Talk, fields=['speakers'], widgets={'speakers': widget})
diff --git a/cfp/views.py b/cfp/views.py
index 0334429..7be8dcd 100644
--- a/cfp/views.py
+++ b/cfp/views.py
@@ -26,7 +26,7 @@ from .decorators import speaker_required, volunteer_required, staff_required
 from .mixins import StaffRequiredMixin, OnSiteMixin, OnSiteFormMixin
 from .utils import is_staff
 from .models import Participant, Talk, TalkCategory, Vote, Track, Tag, Room, Volunteer, Activity
-from .forms import TalkForm, TalkStaffForm, TalkFilterForm, TalkActionForm, TalkSpeakerForm, \
+from .forms import TalkForm, TalkStaffForm, TalkFilterForm, TalkActionForm, get_talk_speaker_form_class, \
                    ParticipantForm, ParticipantFilterForm, NotifyForm, \
                    ConferenceForm, HomepageForm, CreateUserForm, TrackForm, RoomForm, \
                    VolunteerForm, VolunteerFilterForm, MailForm, \
@@ -708,7 +708,7 @@ def talk_decide(request, talk_id, accept):
 @staff_required
 def talk_speaker_add(request, talk_id):
     talk = get_object_or_404(Talk, pk=talk_id, site=request.conference.site)
-    form = TalkSpeakerForm(request.POST or None, instance=talk)
+    form = get_talk_speaker_form_class(site=talk.site)(request.POST or None, instance=talk)
     if request.method == 'POST' and form.is_valid():
         form.save()
         messages.success(request, _('Decision taken in account'))