diff --git a/dbfilter_from_header/__init__.py b/dbfilter_from_header/__init__.py
index 14138f080..02682cd83 100644
--- a/dbfilter_from_header/__init__.py
+++ b/dbfilter_from_header/__init__.py
@@ -19,8 +19,10 @@
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 ##############################################################################
+import logging
 import re
 from openerp import http
+from openerp.tools import config
 
 db_filter_org = http.db_filter
 
@@ -38,4 +40,8 @@ def db_filter(dbs, httprequest=None):
         dbs = [db for db in dbs if re.match(db_filter_hdr, db)]
     return dbs
 
-http.db_filter = db_filter
+if config.get('proxy_mode') and \
+   'dbfilter_from_header' in config.get('server_wide_modules'):
+    _logger = logging.getLogger(__name__)
+    _logger.info('monkey patching http.db_filter')
+    http.db_filter = db_filter
diff --git a/dbfilter_from_header/__openerp__.py b/dbfilter_from_header/__openerp__.py
index 766fd0b9f..1b693d49c 100644
--- a/dbfilter_from_header/__openerp__.py
+++ b/dbfilter_from_header/__openerp__.py
@@ -34,6 +34,8 @@
     proxy_set_header X-OpenERP-dbfilter [your filter];
     proxy_set_header X-Odoo-dbfilter [your filter];
 
+    Then make sure that proxy_mode = True in Odoo's configuration file.
+
     The addon has to be loaded as server-wide module.
     """,
     "category": "Tools",