diff --git a/uffd/user/models.py b/uffd/user/models.py
index 42a0f12be576287c0584e4a59ccd75e2fdc9545a..a2b8412aa6fdeaaa0b81423dbfcbed47ffc3a86b 100644
--- a/uffd/user/models.py
+++ b/uffd/user/models.py
@@ -109,6 +109,7 @@ class User():
 		if not ldap.loginname_is_safe(value):
 			return False
 		self.loginname = value
+		self.dn = ldap.loginname_to_dn(self.loginname)
 		return True
 
 	def set_displayname(self, value):