diff --git a/docs/user/advanced.rst b/docs/user/advanced.rst
index 503b3f86..bffc7c03 100644
--- a/docs/user/advanced.rst
+++ b/docs/user/advanced.rst
@@ -240,6 +240,9 @@ Note that connections are only released back to the pool for reuse once all body
 data has been read; be sure to either set ``stream`` to ``False`` or read the
 ``content`` property of the ``Response`` object.
 
+Also note that you may have to set manually the ``'Connection': 'keep-alive'`` header to force the server keeping
+the connection open.
+This header is set by default by Chrome, Firefox, IE and opera but isn't set by urllib.
 
 Streaming Uploads
 -----------------