diff --git a/apps/sso/tests.py b/apps/sso/tests.py
index b903cab..89a7f27 100644
--- a/apps/sso/tests.py
+++ b/apps/sso/tests.py
@@ -8,16 +8,20 @@
 
 class MiddlewareTestCase(test_utils.TestCase):
     """Test our custom middleware(s)."""
-
-    def test_httponly(self):
+    def _login(self):
+        """Create a new user and log them in."""
         uid = 'john'
         pw = 'johnpw'
         User.objects.create_user(uid,'lennon@thebeatles.com', pw)
-        r = self.client.post(reverse('cas_login'), {
-            'username': uid, 'password': pw})
+        self.client.login(username=uid, password=pw)
 
-        # No errors
-        eq_(r.status_code, 200)
+    def test_httponly(self):
+        self._login()
+
+        r = self.client.get(reverse('cas_login'))
+
+        # No errors, and we are logged in
+        eq_(r.status_code, 302)
 
         # We have cookies and all are httponly unless specified otherwise.
         self.assertTrue(len(r.cookies) > 0)
@@ -30,3 +34,16 @@ def test_x_frame_options(self):
         r = self.client.get(reverse('cas_login'))
         eq_(r.status_code, 200)
         eq_(r['x-frame-options'], 'DENY')
+
+    def test_session_ip_check(self):
+        """Make sure our session cookies are tied to a single IP."""
+        different_forwarded_for = '192.168.0.1, 192.168.0.2'
+
+        self._login()
+
+        r = self.client.get(reverse('home'))
+        self.assertTrue(r.context['user'].is_authenticated())
+
+        r = self.client.get(reverse('home'),
+                            HTTP_X_FORWARDED_FOR=different_forwarded_for)
+        self.assertFalse(r.context['user'].is_authenticated())
diff --git a/apps/users/views.py b/apps/users/views.py
index 9516e08..5d3fb04 100644
--- a/apps/users/views.py
+++ b/apps/users/views.py
@@ -18,6 +18,7 @@ def display_profile(request):
 def edit_profile(request):
     return HttpResponse('edit profile page')
 
+
 def register(request):
     """ Given a username, email, and password, creates a new user """
 
diff --git a/requirements/prod.txt b/requirements/prod.txt
index e97e768..a10f2ad 100644
--- a/requirements/prod.txt
+++ b/requirements/prod.txt
@@ -4,5 +4,8 @@ Django==1.2.1
 -e git://github.com/jbalogh/jingo.git#egg=jingo
 -e git://github.com/jsocol/commonware.git#egg=commonware
 
+# Security
+-e git://github.com/rfk/django-paranoid-sessions.git#egg=paranoidsessions
+
 # Caching
 python-memcached==1.45
diff --git a/settings.py b/settings.py
index 3fed73c..5c058ff 100644
--- a/settings.py
+++ b/settings.py
@@ -113,10 +113,11 @@ def JINJA_CONFIG():
 
 
 MIDDLEWARE_CLASSES = (
+    'commonware.middleware.SetRemoteAddrFromForwardedFor', # First, so all others see the right IP
     'sso.middleware.HttpOnlyMiddleware',  # needs to be before AuthMiddleware
-
     'django.middleware.common.CommonMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
+    'paranoidsessions.ParanoidSessionMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.middleware.csrf.CsrfResponseMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
@@ -147,7 +148,6 @@ def JINJA_CONFIG():
 TEST_RUNNER = 'test_utils.runner.RadicalTestSuiteRunner'
 
 # Security settings
-
 SESSION_EXPIRE_AT_BROWSER_CLOSE = True
 # Default to 1 week expiration
 SESSION_COOKIE_AGE = 7 * 24 * 60 * 60
@@ -156,9 +156,13 @@ def JINJA_CONFIG():
 # Cookie names that should NOT have the HttpOnly flag set.
 JAVASCRIPT_READABLE_COOKIES = ()
 
-# Service ticket expiration, in seconds, 0 means no expiration.
+# CAS Service ticket expiration, in seconds, 0 means no expiration.
 SERVICE_TICKET_TIMEOUT = 30
 
+# django-paranoid-sessions settings
+PSESSION_CHECK_HEADERS = ('REMOTE_ADDR',)  # Check remote IP address
+PSESSION_NONCE_TIMEOUT = None  # No nonce cookies for now
+
 # Emails
 DEFAULT_FROM_EMAIL = 'nobody@mozilla.org'
 EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'