diff --git a/gvaldap/ldapentities/models.py b/gvaldap/ldapentities/models.py
index 0fd72f3..7d0d609 100644
--- a/gvaldap/ldapentities/models.py
+++ b/gvaldap/ldapentities/models.py
@@ -39,16 +39,16 @@ class LdapGroup(ldapmodels.Model):
     # LDAP meta-data
     base_dn = settings.GROUP_BASE_DN
     #: list of object classes
-    object_classes = ['posixGroup']
+    object_classes = [b'posixGroup']
 
     # posixGroup attributes
     #: group id (`gidNumber`)
-    gid = IntegerField(db_column='gidNumber', unique=True)
+    gid = IntegerField(db_column=b'gidNumber', unique=True)
     #: group name (`cn`)
-    name = CharField(db_column='cn', max_length=200, primary_key=True)
+    name = CharField(db_column=b'cn', max_length=200, primary_key=True)
     #: group description (`description`)
-    description = CharField(db_column='description')
-    members = ListField(db_column='memberUid', blank=True)
+    description = CharField(db_column=b'description')
+    members = ListField(db_column=b'memberUid', blank=True)
 
     def __str__(self):
         """
@@ -72,25 +72,25 @@ class LdapUser(ldapmodels.Model):
     """
     base_dn = settings.USER_BASE_DN
     #: list of object classes
-    object_classes = ['account', 'posixAccount']
+    object_classes = [b'account', b'posixAccount']
 
     # posixAccount
     #: user id (`uidNumber`)
-    uid = IntegerField(db_column='uidNumber', unique=True)
+    uid = IntegerField(db_column=b'uidNumber', unique=True)
     #: group id (`gidNumber`) of the user's primary group
-    group = IntegerField(db_column='gidNumber')
+    group = IntegerField(db_column=b'gidNumber')
     #: GECOS field (`gecos`)
-    gecos = CharField(db_column='gecos')
+    gecos = CharField(db_column=b'gecos')
     #: home directory (`homeDirectory`)
-    home_directory = CharField(db_column='homeDirectory')
+    home_directory = CharField(db_column=b'homeDirectory')
     #: login shell (`loginShell`)
-    login_shell = CharField(db_column='loginShell', default='/bin/bash')
+    login_shell = CharField(db_column=b'loginShell', default='/bin/bash')
     #: user name (`uid`)
-    username = CharField(db_column='uid', primary_key=True)
+    username = CharField(db_column=b'uid', primary_key=True)
     #: password (`userPassword`) in an LDAP compatible format
-    password = CharField(db_column='userPassword')
+    password = CharField(db_column=b'userPassword')
     #: common name (`cn`)
-    common_name = CharField(db_column='cn')
+    common_name = CharField(db_column=b'cn')
 
     def __str__(self):
         """