diff --git a/helpdesk/forms.py b/helpdesk/forms.py
index b766ceb6..75367e19 100644
--- a/helpdesk/forms.py
+++ b/helpdesk/forms.py
@@ -540,6 +540,16 @@ class TicketCCForm(forms.ModelForm):
         model = TicketCC
         exclude = ('ticket',)
 
+    def clean(self):
+
+        cleaned_data = super(TicketCCForm, self).clean()
+
+        user = cleaned_data.get('user', None)
+        email = cleaned_data.get('email', '')
+
+        if user is None and len(email) == 0:
+            raise forms.ValidationError(_('When you add somebody on Cc, you must provided either an User or a valid email.'))
+
 class TicketDependencyForm(forms.ModelForm):
     class Meta:
         model = TicketDependency