diff --git a/docs/user/quickstart.rst b/docs/user/quickstart.rst
index 59d75ccb..660cdfa2 100644
--- a/docs/user/quickstart.rst
+++ b/docs/user/quickstart.rst
@@ -71,6 +71,9 @@ You can see that the URL has been correctly encoded by printing the URL::
     >>> print r.url
     u'http://httpbin.org/get?key2=value2&key1=value1'
 
+Note that any dictionary key whose value is ``None`` will not be added to the
+URL's query string.
+
 
 Response Content
 ----------------