diff --git a/radicale.wsgi b/radicale.wsgi
index 87c330b9..211b6c78 100644
--- a/radicale.wsgi
+++ b/radicale.wsgi
@@ -3,4 +3,8 @@ Radicale WSGI file (mod_wsgi and uWSGI compliant).
 
 """
 
+import os
 from radicale import application
+
+# set an environment variable
+os.environ.setdefault('SERVER_GATEWAY_INTERFACE', 'Web')