diff --git a/accounts/forms.py b/accounts/forms.py
index c254798..c9e54f5 100644
--- a/accounts/forms.py
+++ b/accounts/forms.py
@@ -99,6 +99,8 @@ def clean_email(self):
             raise forms.ValidationError(u'E-mail address is already taken.')
         except User.DoesNotExist:
             pass
+        except User.MultipleObjectsReturned:
+            raise forms.ValidationError(u'E-mail address is already taken.')
         return email
 
     def save(self):