diff --git a/invenio/ext/iiif/__init__.py b/invenio/ext/iiif/__init__.py
index 564b3596b..8d0ea8fe6 100644
--- a/invenio/ext/iiif/__init__.py
+++ b/invenio/ext/iiif/__init__.py
@@ -1,73 +1,76 @@
 # -*- coding: utf-8 -*-
 #
 # This file is part of Invenio.
 # Copyright (C) 2015 CERN.
 #
 # Invenio is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License as
 # published by the Free Software Foundation; either version 2 of the
 # License, or (at your option) any later version.
 #
 # Invenio is distributed in the hope that it will be useful, but
 # WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 # General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with Invenio; if not, write to the Free Software Foundation, Inc.,
 # 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 
 """Flask-IIIF extension.
 
 .. py:data:: IIIF_IMAGE_OPENER
 
     There are two ways to initialize an IIIF image object, by ``fullpath`` and
     ``bytestream``. Can be an ``import string`` or a ``callback function``.
     By default ``identifier_to_path`` return the ``fullpath`` of
     :class:`~invenio.modules.documents.api:Document`.
 
     default: :func:`~invenio.modules.documents.utis.identifier_to_path`
 """
 
 from flask_iiif import IIIF
 from flask_iiif.errors import MultimediaError
 
 from six import string_types
 
 from werkzeug.utils import import_string
 
 from .utils import api_file_permission_check
 
 __all__ = ('setup_app', )
 
 iiif = IIIF()
 
 
 def setup_app(app):
     """Setup Flask-IIIF extension."""
     if 'invenio.modules.documents' in app.config.get('PACKAGES_EXCLUDE'):
         raise MultimediaError(
             "Could not initialize the Flask-IIIF extension because "
             ":class:`~invenio.modules.documents.api:Document` is missing"
         )
 
     iiif.init_app(app)
     iiif.init_restful(app.extensions['restful'])
     app.config.setdefault(
         'IIIF_IMAGE_OPENER',
         'invenio.modules.documents.utils:identifier_to_path'
     )
 
     uuid_to_source_handler = app.config['IIIF_IMAGE_OPENER']
 
     uuid_to_source = (
         import_string(uuid_to_source_handler) if
         isinstance(uuid_to_source_handler, string_types) else
         uuid_to_source_handler
     )
     iiif.uuid_to_image_opener_handler(uuid_to_source)
-    app.config['IIIF_CACHE_HANDLER'] = 'invenio.ext.cache:cache'
+    app.config.setdefault(
+        'IIIF_CACHE_HANDLER',
+        'invenio.ext.cache:cache'
+    )
 
     # protect the api
     iiif.api_decorator_handler(api_file_permission_check)
     return app