diff --git a/pykolab/logger.py b/pykolab/logger.py
--- a/pykolab/logger.py
+++ b/pykolab/logger.py
@@ -213,7 +213,7 @@
                                 group_gid
                             )
 
-                            os.chmod(self.logfile, 660)
+                            os.chmod(self.logfile, 0660)
 
                     except Exception as errmsg:
                         self.error(
diff --git a/pykolab/setup/setup_mysql.py b/pykolab/setup/setup_mysql.py
--- a/pykolab/setup/setup_mysql.py
+++ b/pykolab/setup/setup_mysql.py
@@ -230,7 +230,7 @@
 """ % (mysql_root_password, conf.mysqlhost)
 
     fp = open('/tmp/kolab-setup-my.cnf', 'w')
-    os.chmod('/tmp/kolab-setup-my.cnf', 600)
+    os.chmod('/tmp/kolab-setup-my.cnf', 0600)
     fp.write(data)
     fp.close()
 
diff --git a/pykolab/setup/setup_roundcube.py b/pykolab/setup/setup_roundcube.py
--- a/pykolab/setup/setup_roundcube.py
+++ b/pykolab/setup/setup_roundcube.py
@@ -236,7 +236,7 @@
 """ % (mysql_root_password, conf.mysqlhost)
 
         fp = open('/tmp/kolab-setup-my.cnf', 'w')
-        os.chmod('/tmp/kolab-setup-my.cnf', 600)
+        os.chmod('/tmp/kolab-setup-my.cnf', 0600)
         fp.write(data)
         fp.close()