diff --git a/django/test/client.py b/django/test/client.py
index dd0d811..f4b8d63 100644
--- a/django/test/client.py
+++ b/django/test/client.py
@@ -358,13 +358,18 @@ class Client(RequestFactory):
         """
         if 'django.contrib.sessions' in settings.INSTALLED_APPS:
             engine = import_module(settings.SESSION_ENGINE)
-            cookie = self.cookies.get(settings.SESSION_COOKIE_NAME, None)
+            cookie = self.cookies.get(settings.SESSION_COOKIE_NAME)
             if cookie:
                 return engine.SessionStore(cookie.value)
+            else:
+                session_store = engine.SessionStore()
+                session_store.save()
+                self.cookies[settings.SESSION_COOKIE_NAME] = \
+                    session_store.session_key
+                return session_store
         return {}
     session = property(_session)
 
-
     def request(self, **request):
         """
         The master request method. Composes the environment dictionary
diff --git a/tests/regressiontests/test_client_regress/models.py b/tests/regressiontests/test_client_regress/models.py
index b24032d..9f415a4 100644
--- a/tests/regressiontests/test_client_regress/models.py
+++ b/tests/regressiontests/test_client_regress/models.py
@@ -690,6 +690,17 @@ class SessionTests(TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content, 'YES')
 
+    def test_session_manipulation(self):
+        # Modify the session
+        session = self.client.session
+        session["session_var"] = "foo"
+        session.save()
+
+        # Check that the session works in the client
+        response = self.client.get('/test_client_regress/check_session/')
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.content, 'foo')
+
     def test_logout(self):
         """Logout should work whether the user is logged in or not (#9978)."""
         self.client.logout()