diff --git a/swh/web/manage.py b/swh/web/manage.py
--- a/swh/web/manage.py
+++ b/swh/web/manage.py
@@ -16,12 +16,13 @@
     # in swh/web/urls.py, we pass the nostatic options to runserver
     # in order to have gzip compression enabled.
     swh_web_config['serve_assets'] = '--nostatic' in sys.argv
-    if len(sys.argv) > 1 and sys.argv[1] == 'test':
-        os.environ.setdefault("DJANGO_SETTINGS_MODULE",
-                              "swh.web.settings.tests")
-    else:
-        os.environ.setdefault("DJANGO_SETTINGS_MODULE",
-                              "swh.web.settings.development")
+    if 'DJANGO_SETTINGS_MODULE' not in os.environ:
+        if len(sys.argv) > 1 and sys.argv[1] == 'test':
+            os.environ.setdefault("DJANGO_SETTINGS_MODULE",
+                                  "swh.web.settings.tests")
+        else:
+            os.environ.setdefault("DJANGO_SETTINGS_MODULE",
+                                  "swh.web.settings.development")
     # import root urls module for swh-web before running the django dev server
     # in order to ensure it will be automatically reloaded when source files
     # are modified (as django autoreload feature only works if the modules are
@@ -31,7 +32,7 @@
     except Exception:
         pass
     try:
-        from django.core.management.commands.runserver import (
+        from django.core.management.commands.runserver import (  # noqa: N813
             Command as runserver
         )
         from django.core.management import execute_from_command_line