diff --git a/modoboa/core/management/commands/clean_unknown_extensions.py b/modoboa/core/management/commands/clean_unknown_extensions.py
index 12efa29fe..f22c13852 100644
--- a/modoboa/core/management/commands/clean_unknown_extensions.py
+++ b/modoboa/core/management/commands/clean_unknown_extensions.py
@@ -6,6 +6,7 @@ database.
 """
 from django.conf import settings
 from django.core.management.base import BaseCommand
+from django.db import connection
 
 from modoboa.core.models import Extension
 
@@ -22,3 +23,4 @@ class Command(BaseCommand):
             fullname = "modoboa.extensions.{0}".format(extension.name)
             if not fullname in settings.MODOBOA_APPS:
                 extension.delete()
+        connection.close()
diff --git a/modoboa/core/management/commands/cleanlogs.py b/modoboa/core/management/commands/cleanlogs.py
index 59f3859d9..12bdba04c 100644
--- a/modoboa/core/management/commands/cleanlogs.py
+++ b/modoboa/core/management/commands/cleanlogs.py
@@ -1,10 +1,12 @@
-#!/usr/bin/env python
 # coding: utf-8
+
 import datetime
 from optparse import make_option
-from django import db
+
+from django.db import connection
 from django.core.management.base import BaseCommand
 from django.utils import timezone
+
 from modoboa.core import load_core_settings
 from modoboa.core.models import Log
 from modoboa.lib import parameters
@@ -43,5 +45,5 @@ class Command(BaseCommand):
         self.__vprint("Deleting logs older than %d days..." % log_maximum_age)
         limit = timezone.now() - datetime.timedelta(log_maximum_age)
         Log.objects.filter(date_created__lt=limit).delete()
-        db.close_connection()
+        connection.close()
         self.__vprint("Done.")
diff --git a/modoboa/core/management/commands/manage_extensions.py b/modoboa/core/management/commands/manage_extensions.py
index 2fa71b847..349a26a44 100644
--- a/modoboa/core/management/commands/manage_extensions.py
+++ b/modoboa/core/management/commands/manage_extensions.py
@@ -6,6 +6,7 @@ from optparse import make_option
 
 from django.conf import settings
 from django.core.management.base import BaseCommand
+from django.db import connection
 
 from modoboa.core.models import Extension
 
@@ -55,3 +56,5 @@ class Command(BaseCommand):
             if not fullname in settings.MODOBOA_APPS:
                 continue
             self._change_extension_state(extname, options)
+
+        connection.close()
diff --git a/modoboa/core/management/commands/set_default_site.py b/modoboa/core/management/commands/set_default_site.py
index 03f703267..8626f2722 100644
--- a/modoboa/core/management/commands/set_default_site.py
+++ b/modoboa/core/management/commands/set_default_site.py
@@ -6,6 +6,7 @@ See `https://docs.djangoproject.com/en/dev/ref/contrib/sites/`_.
 """
 
 from django.core.management.base import BaseCommand, CommandError
+from django.db import connection
 
 from django.contrib.sites.models import Site
 
@@ -24,3 +25,4 @@ class Command(BaseCommand):
         site.domain = args[0]
         site.name = args[0]
         site.save()
+        connection.close()
diff --git a/modoboa/extensions/admin/management/commands/handle_mailbox_operations.py b/modoboa/extensions/admin/management/commands/handle_mailbox_operations.py
index e282fb1c6..e17b4e236 100644
--- a/modoboa/extensions/admin/management/commands/handle_mailbox_operations.py
+++ b/modoboa/extensions/admin/management/commands/handle_mailbox_operations.py
@@ -1,8 +1,11 @@
-import os
+
 import logging
 from optparse import make_option
-from django import db
+import os
+
 from django.core.management.base import BaseCommand
+from django.db import connection
+
 from modoboa.lib import parameters
 from modoboa.lib.sysutils import exec_cmd
 from modoboa.lib.exceptions import InternalError
@@ -91,4 +94,4 @@ class Command(BaseCommand):
                 self.logger.info('%s succeed', ope)
                 ope.delete()
         os.unlink(options['pidfile'])
-        db.close_connection()
+        connection.close()
diff --git a/modoboa/extensions/amavis/management/commands/amnotify.py b/modoboa/extensions/amavis/management/commands/amnotify.py
index b563e7fb2..87e7be8f0 100644
--- a/modoboa/extensions/amavis/management/commands/amnotify.py
+++ b/modoboa/extensions/amavis/management/commands/amnotify.py
@@ -2,7 +2,7 @@
 # coding: utf-8
 from optparse import make_option
 
-from django import db
+from django.db import connection
 from django.core.management.base import BaseCommand, CommandError
 from django.template.loader import render_to_string
 from django.core.urlresolvers import reverse
@@ -94,4 +94,4 @@ class Command(BaseCommand):
                 continue
             rcpt = su.mailbox_set.all()[0].full_address
             self.send_pr_notification(rcpt, reqs)
-        db.close_connection()
+        connection.close()
diff --git a/modoboa/extensions/amavis/management/commands/qcleanup.py b/modoboa/extensions/amavis/management/commands/qcleanup.py
index a1be4a32d..141c6f251 100644
--- a/modoboa/extensions/amavis/management/commands/qcleanup.py
+++ b/modoboa/extensions/amavis/management/commands/qcleanup.py
@@ -3,7 +3,7 @@
 
 import time
 from optparse import make_option
-from django import db
+from django.db import connection
 from django.core.management.base import BaseCommand
 from modoboa.lib import parameters
 from modoboa.extensions.amavis import Amavis
@@ -64,6 +64,6 @@ class Command(BaseCommand):
         for maddr in Maddr.objects.all():
             if not maddr.msgs_set.count() and not maddr.msgrcpt_set.count():
                 maddr.delete()
-        db.close_connection()
+        connection.close()
 
         self.__vprint("Done.")
diff --git a/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py b/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py
index f91645a4e..3a7b1bcc8 100644
--- a/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py
+++ b/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py
@@ -2,9 +2,11 @@
 # coding: utf-8
 import sys
 import datetime
-from django import db
+
+from django.db import connection
 from django.core.management.base import BaseCommand, CommandError
 from django.utils import timezone
+
 from modoboa.lib import parameters
 from modoboa.lib.emailutils import split_mailbox, sendmail_simple
 from modoboa.extensions.admin.models import Mailbox
@@ -65,4 +67,4 @@ class Command(BaseCommand):
                 continue
 
             send_autoreply(sender, mbox, armessage)
-        db.close_connection()
+        connection.close()
diff --git a/modoboa/extensions/stats/management/commands/logparser.py b/modoboa/extensions/stats/management/commands/logparser.py
index 8031df1d3..f113bd6bb 100644
--- a/modoboa/extensions/stats/management/commands/logparser.py
+++ b/modoboa/extensions/stats/management/commands/logparser.py
@@ -25,7 +25,7 @@ import rrdtool
 import string
 from optparse import make_option
 
-from django import db
+from django.db import connection
 from django.core.management.base import BaseCommand
 
 from modoboa.core.extensions import exts_pool
@@ -372,4 +372,4 @@ class Command(BaseCommand):
             options["logfile"] = parameters.get_admin("LOGFILE", app="stats")
         p = LogParser(options, parameters.get_admin("RRD_ROOTDIR", app="stats"))
         p.process()
-        db.close_connection()
+        connection.close()