diff --git a/apps/member/views.py b/apps/member/views.py
index 75f6341..200d417 100644
--- a/apps/member/views.py
+++ b/apps/member/views.py
@@ -126,7 +126,7 @@ class JoinTeamView(LoginRequiredMixin, FormView):
             form.add_error('access_code', _("This team is full of coachs."))
             return self.form_invalid(form)
 
-        if self.request.user.role == '3participant' and len(team.participants.size()) == 5:
+        if self.request.user.role == '3participant' and len(team.participants) == 6:
             form.add_error('access_code', _("This team is full of participants."))
             return self.form_invalid(form)