diff -r f4dec0cca9a1 -r 84468b90e9c1 server/test/unittest_ldapsource.py
--- a/server/test/unittest_ldapsource.py	Wed Sep 16 11:23:51 2015 +0200
+++ b/server/test/unittest_ldapsource.py	Mon Sep 14 16:03:07 2015 +0200
@@ -26,6 +26,7 @@
 import subprocess
 import tempfile
 
+from six import string_types
 from six.moves import range
 
 from logilab.common.testlib import TestCase, unittest_main, mock_object, Tags
@@ -155,7 +156,7 @@
         """
         modcmd = ['dn: %s'%dn, 'changetype: add']
         for key, values in mods.iteritems():
-            if isinstance(values, basestring):
+            if isinstance(values, string_types):
                 values = [values]
             for value in values:
                 modcmd.append('%s: %s'%(key, value))
@@ -175,7 +176,7 @@
         modcmd = ['dn: %s'%dn, 'changetype: modify']
         for (kind, key), values in mods.iteritems():
             modcmd.append('%s: %s' % (kind, key))
-            if isinstance(values, basestring):
+            if isinstance(values, string_types):
                 values = [values]
             for value in values:
                 modcmd.append('%s: %s'%(key, value))