diff --git a/bin/swh-web-dev b/bin/swh-web-dev
index 0a6bfe07..15c30c8a 100755
--- a/bin/swh-web-dev
+++ b/bin/swh-web-dev
@@ -1,45 +1,48 @@
 #!/usr/bin/env python3
 
 # Copyright (C) 2015  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU Affero General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 
 import argparse
 import django
 import os
 
-from django.core import management
+# need to setup django settings before importing django modules
+# with django 1.7 (debian jessie)
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "swh.web.settings") # noqa
 
-from django.core.management.commands.runserver import (
+from django.core import management # noqa
+
+from django.core.management.commands.runserver import ( # noqa
     Command as runserver
 )
 
-from swh.web import config
+from swh.web import config # noqa
 
 # Default configuration file
 DEFAULT_CONF_FILE = '~/.config/swh/webapp.yml'
 
 
 def parse_args():
     """Parse the configuration for the cli.
     """
     cli = argparse.ArgumentParser(description="SWH's web ui.")
 
     cli.add_argument('--config', '-c', help='configuration file path')
 
     args = cli.parse_args()
 
     return args
 
 
 if __name__ == '__main__':
     args = parse_args()
     config_path = args.config or DEFAULT_CONF_FILE
     swh_web_config = config.get_config(config_path)
     runserver.default_port = swh_web_config['port']
     runserver.default_addr = swh_web_config['host']
-    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "swh.web.settings")
     django.setup()
     management.call_command('runserver')
diff --git a/swh/web/api/templates/apidoc.html b/swh/web/api/templates/apidoc.html
index cf519977..ed207309 100644
--- a/swh/web/api/templates/apidoc.html
+++ b/swh/web/api/templates/apidoc.html
@@ -1,137 +1,137 @@
 {% extends "layout.html" %}
 {% load api_extras %}
 {% block title %}{{ heading }} – Software Heritage API {% endblock %}
 {% block content %}
 <nav class="bread-crumbs">
   <ul>
     <li><a href="/api/">API</a></li>
     <li>/</li>
     <li><a href="/api/1/">endpoints</a></li>
     <li>/</li>
     <li>{{ request.path }}</li>
   </ul>
 </nav>
 
 {% if docstring %}
 <div class="docstring">
   <h2> Description </h2>
   {{ docstring | safe_docstring_display | safe }}
 </div>
 {% endif %}
-{% if response_data and response_data is not none %}
+{% if response_data  %}
 <div class="response-data">
   <h2>Request</h2>
   <pre><strong>{{ request.method }}</strong> {{ request.build_absolute_uri }}</pre>
   <hr/>
   <h2>Response</h2>
   {% if status_code != 200 %}
   <h3>Status Code</h3>
   <pre class="error">{{ status_code }}</pre>
   {% endif %}
-  {% if headers_data and headers_data is not none %}
+  {% if headers_data %}
   <h3>Headers</h3>
     {% for header_name, header_value in headers_data.items %}
       <pre><strong>{{ header_name }}</strong> {{ header_value | urlize_header_links | safe }}</pre>
     {% endfor %}
   {% endif %}
     <h3>Body</h3>
     {{ response_data | highlight_json | urlize_api_links | safe }}
 </div>
 {% endif %}
 <hr/>
 {% if urls and urls|length > 0 %}
 <div class="doc-urls">
   <table class="m-x-auto table">
     <thead>
       <tr>
 	<th>URL</th>
 	<th>Allowed Methods</th>
       </tr>
     </thead>
     <tbody>
       {% for url in urls %}
       <tr>
 	<td>
 	  {{ url.rule }}
 	</td>
 	<td>
 	  {{ url.methods | dictsort:0 | join:', ' }}
 	</td>
       </tr>
       {% endfor %}
     </tbody>
   </table>
 </div>
 <hr/>
 {% endif %}
 {% if args and args|length > 0 %}
 <div class="doc-args">
   <h2> Arguments </h2>
   <dl class="doc-argslist dl-horizontal">
     {% for arg in args %}
     <dt> {{ arg.name }}: {{ arg.type }} </dt>
     <dd> {{ arg.doc | safe_docstring_display | safe }} </dd>
     {% endfor %}
   </dl>
 </div>
 <hr/>
 {% endif %}
 {% if params and params|length > 0 %}
 <div class="doc-params">
   <h2> Parameters </h2>
   <dl class="doc-paramslist dl-horizontal">
     {% for param in params %}
     <dt> {{ param.name }}: {{ param.type }} </dt>
     <dd> {{ param.doc | safe_docstring_display | safe }} </dd>
     {% endfor %}
   </dl>
 </div>
 <hr/>
 {% endif %}
 {% if headers %}
 <div class="doc-headers">
   <h2> Headers </h2>
   <dl class="doc-headers dl-horizontal">
     {% for header in headers %}
     <dt> {{ header.name }}: string </dt>
     <dd> {{ header.doc | safe_docstring_display | safe }} </dd>
     {% endfor %}
   </dl>
 </div>
 <hr/>
 {% endif %}
 {% if return %}
 <div class="doc-return">
   <h2> Returns </h2>
   <dl class="doc-return dl-horizontal">
     <dt> {{ return.type }} </dt>
     <dd> {{ return.doc | safe_docstring_display | safe }} </dd>
   </dl>
 </div>
 <hr/>
 {% endif %}
 {% if excs and excs|length > 0 %}
 <div class="doc-excs">
     <h2> Errors </h2>
     <dl class="doc-excslist dl-horizontal">
         {% for exc in excs %}
         <dt> {{ exc.exc }} </dt>
         <dd> {{ exc.doc | safe_docstring_display | safe }} </dd>
         {% endfor %}
     </dl>
 </div>
 <hr/>
 {% endif %}
 {% if examples %}
 <div class="doc-example">
   <h2> Examples </h2>
   <dl class="doc-example dl-horizontal">
   {% for example in examples %}
     <dd>
       <a href="{{ example }}">{{ example }}</a>
     </dd>
   {% endfor %}
   </dl>
 </div>
 {% endif %}
 {% endblock %}
diff --git a/swh/web/settings.py b/swh/web/settings.py
index 19144893..ec0df993 100644
--- a/swh/web/settings.py
+++ b/swh/web/settings.py
@@ -1,183 +1,185 @@
 # Copyright (C) 2017  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 
 """
 Django settings for swhweb project.
 
 Generated by 'django-admin startproject' using Django 1.11.3.
 
 For more information on this file, see
 https://docs.djangoproject.com/en/1.11/topics/settings/
 
 For the full list of settings and their values, see
 https://docs.djangoproject.com/en/1.11/ref/settings/
 """
 
 import os
 
 from swh.web.config import get_config
 
 swh_web_config = get_config()
 
 # Build paths inside the project like this: os.path.join(BASE_DIR, ...)
 PROJECT_DIR = os.path.dirname(os.path.abspath(__file__))
 
 # Quick-start development settings - unsuitable for production
 # See https://docs.djangoproject.com/en/1.11/howto/deployment/checklist/
 
 # SECURITY WARNING: keep the secret key used in production secret!
 SECRET_KEY = swh_web_config['secret_key']
 
 # SECURITY WARNING: don't run with debug turned on in production!
 DEBUG = swh_web_config['debug']
 
 ALLOWED_HOSTS = ['127.0.0.1', 'localhost', 'testserver']
 
 # Application definition
 
 INSTALLED_APPS = [
     'django.contrib.admin',
     'django.contrib.auth',
     'django.contrib.contenttypes',
     'django.contrib.sessions',
     'django.contrib.messages',
     'django.contrib.staticfiles',
     'rest_framework',
     'swh.web.api'
 ]
 
 MIDDLEWARE = [
     'django.middleware.security.SecurityMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
     'django.middleware.clickjacking.XFrameOptionsMiddleware',
 ]
 
 ROOT_URLCONF = 'swh.web.urls'
 
 TEMPLATES = [
     {
         'BACKEND': 'django.template.backends.django.DjangoTemplates',
         'DIRS': [],
         'APP_DIRS': True,
         'OPTIONS': {
             'context_processors': [
                 'django.template.context_processors.debug',
                 'django.template.context_processors.request',
                 'django.contrib.auth.context_processors.auth',
                 'django.contrib.messages.context_processors.messages',
             ],
         },
     },
 ]
 
 WSGI_APPLICATION = 'swh.web.wsgi.application'
 
 
 # Database
 # https://docs.djangoproject.com/en/1.11/ref/settings/#databases
 
 DATABASES = {
     'default': {
         'ENGINE': 'django.db.backends.sqlite3',
         'NAME': os.path.join(PROJECT_DIR, 'db.sqlite3'),
     }
 }
 
 # Password validation
 # https://docs.djangoproject.com/en/1.11/ref/settings/#auth-password-validators
 
 AUTH_PASSWORD_VALIDATORS = [
     {
         'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',  # noqa
     },
     {
         'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',  # noqa
     },
     {
         'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',  # noqa
     },
     {
         'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',  # noqa
     },
 ]
 
 
 # Internationalization
 # https://docs.djangoproject.com/en/1.11/topics/i18n/
 
 LANGUAGE_CODE = 'en-us'
 
 TIME_ZONE = 'UTC'
 
 USE_I18N = True
 
 USE_L10N = True
 
 USE_TZ = True
 
 # Static files (CSS, JavaScript, Images)
 # https://docs.djangoproject.com/en/1.11/howto/static-files/
 
 STATIC_URL = '/static/'
 STATICFILES_DIRS = [
     os.path.join(PROJECT_DIR, "static")
 ]
 
 INTERNAL_IPS = ['127.0.0.1']
 
 throttle_rates = {}
 
 for limiter_scope, limiter_conf in swh_web_config['limiters'].items():
     throttle_rates[limiter_scope] = None if DEBUG else limiter_conf['limiter_rate'] # noqa
 
 REST_FRAMEWORK = {
     'DEFAULT_RENDERER_CLASSES': (
         'rest_framework.renderers.JSONRenderer',
         'swh.web.api.renderers.YAMLRenderer',
         'rest_framework.renderers.TemplateHTMLRenderer'
     ),
     'DEFAULT_THROTTLE_CLASSES': (
         'swh.web.common.throttling.SwhWebRateThrottle',
     ),
     'DEFAULT_THROTTLE_RATES': throttle_rates
 }
 
 LOGGING = {
     'version': 1,
     'disable_existing_loggers': False,
     'filters': {
         'require_debug_false': {
             '()': 'django.utils.log.RequireDebugFalse',
         },
         'require_debug_true': {
             '()': 'django.utils.log.RequireDebugTrue',
         },
     },
     'handlers': {
         'console': {
             'level': 'INFO',
             'filters': ['require_debug_true'],
             'class': 'logging.StreamHandler',
         },
         'file': {
             'level': 'DEBUG',
             'filters': ['require_debug_false'],
             'class': 'logging.FileHandler',
             'filename': os.path.join(swh_web_config['log_dir'], 'swh-web.log'),
         },
     },
     'loggers': {
         'django': {
             'handlers': ['console', 'file'],
             'level': 'DEBUG',
             'propagate': True,
         },
     },
 }
+
+SILENCED_SYSTEM_CHECKS = ['1_7.W001']