diff --git a/AUTHORS b/AUTHORS
index 92581cf547..e9316b700d 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -35,6 +35,7 @@ answer newbie questions, and generally made Django that much better:
     Andreas
     David Ascher <http://ascher.ca/>
     Arthur <avandorp@gmail.com>
+    Jiri Barton
     James Bennett
     Paul Bissex <http://e-scribe.com/>
     Simon Blanchard
diff --git a/django/middleware/sessions.py b/django/middleware/sessions.py
index 545ee38fa8..d6d25de276 100644
--- a/django/middleware/sessions.py
+++ b/django/middleware/sessions.py
@@ -69,12 +69,13 @@ class SessionMiddleware:
         try:
             modified = request.session.modified
         except AttributeError:
-            modified = False
-        if modified or SESSION_SAVE_EVERY_REQUEST:
-            session_key = request.session.session_key or sessions.get_new_session_key()
-            new_session = sessions.save(session_key, request.session._session,
-                datetime.datetime.now() + datetime.timedelta(seconds=SESSION_COOKIE_AGE))
-            expires = datetime.datetime.strftime(datetime.datetime.utcnow() + datetime.timedelta(seconds=SESSION_COOKIE_AGE), "%a, %d-%b-%Y %H:%M:%S GMT")
-            response.set_cookie(SESSION_COOKIE_NAME, session_key,
-                max_age=SESSION_COOKIE_AGE, expires=expires, domain=SESSION_COOKIE_DOMAIN)
+            pass
+        else:
+            if modified or SESSION_SAVE_EVERY_REQUEST:
+                session_key = request.session.session_key or sessions.get_new_session_key()
+                new_session = sessions.save(session_key, request.session._session,
+                    datetime.datetime.now() + datetime.timedelta(seconds=SESSION_COOKIE_AGE))
+                expires = datetime.datetime.strftime(datetime.datetime.utcnow() + datetime.timedelta(seconds=SESSION_COOKIE_AGE), "%a, %d-%b-%Y %H:%M:%S GMT")
+                response.set_cookie(SESSION_COOKIE_NAME, session_key,
+                    max_age=SESSION_COOKIE_AGE, expires=expires, domain=SESSION_COOKIE_DOMAIN)
         return response