diff --git a/fandjango/settings.py b/fandjango/settings.py
index 27a5460..a1611f3 100644
--- a/fandjango/settings.py
+++ b/fandjango/settings.py
@@ -37,4 +37,4 @@
 FANDJANGO_CACHE_SIGNED_REQUEST = getattr(settings, 'FACEBOOK_SIGNED_REQUEST_COOKIE', True)
 
 # A string describing the website URL.
-FANDJANGO_SITE_URL = getattr(settings, 'FANDJANGO_SITE_URL')
+FANDJANGO_SITE_URL = getattr(settings, 'FANDJANGO_SITE_URL', None)
diff --git a/fandjango/utils.py b/fandjango/utils.py
index 10ef91c..ba4e8e4 100644
--- a/fandjango/utils.py
+++ b/fandjango/utils.py
@@ -76,7 +76,10 @@ def authorization_denied_view(request):
     return authorization_denied_view(request)
 
 def get_post_authorization_redirect_url(request, canvas=True):
-    """Determine the URL users should be redirected to upon authorization the application."""
+    """
+    Determine the URL users should be redirected to upon authorization the application.
+    If request is non-canvas use user defined site url if set, else the site hostname.
+    """
 
     path = request.get_full_path()
 
@@ -90,8 +93,13 @@ def get_post_authorization_redirect_url(request, canvas=True):
             'path': path
         }
     else:
-        path = path.replace(urlparse(FANDJANGO_SITE_URL).path, '')
-        redirect_uri = FANDJANGO_SITE_URL + path
+        if FANDJANGO_SITE_URL:
+            site_url = FANDJANGO_SITE_URL
+            path = path.replace(urlparse(site_url).path, '')
+        else:
+            protocol = "https" if request.is_secure() else "http"
+            site_url = "%s://%s" % (protocol, request.get_host())
+        redirect_uri = site_url + path
 
     return redirect_uri
 
diff --git a/tests/project/settings.py b/tests/project/settings.py
index 7a3fd1d..5bca446 100644
--- a/tests/project/settings.py
+++ b/tests/project/settings.py
@@ -20,8 +20,6 @@
 FACEBOOK_APPLICATION_NAMESPACE = 'fandjango-test'
 FACEBOOK_APPLICATION_CANVAS_URL = 'http://example.org/foo'
 
-FANDJANGO_SITE_URL = FACEBOOK_APPLICATION_CANVAS_URL
-
 SECRET_KEY = '123'
 
 USE_TZ = True
diff --git a/tests/test_fandjango.py b/tests/test_fandjango.py
index 69839cb..aa68cf6 100644
--- a/tests/test_fandjango.py
+++ b/tests/test_fandjango.py
@@ -566,8 +566,8 @@ def test_get_post_authorization_redirect_url(self):
         """
         request = request_factory.get('/foo/bar/baz')
         redirect_url = get_post_authorization_redirect_url(request, canvas = False)
-
-        assert redirect_url == 'http://example.org/foo/bar/baz'
+        # RequestFactory has the hostname "testserver"
+        assert redirect_url == 'http://testserver/foo/bar/baz'
 
     def test_querystring_removal(self):
         """