diff --git a/pep-0574.rst b/pep-0574.rst
index 01a3f0dff..809158807 100644
--- a/pep-0574.rst
+++ b/pep-0574.rst
@@ -298,6 +298,17 @@ The distinction between readonly and writable buffers is explained below
 (see "Mutability").
 
 
+Side effects
+============
+
+Improved in-band performance
+----------------------------
+
+Even in-band pickling can be improved by returning a ``PickleBuffer``
+instance from ``__reduce_ex__``, as one copy is avoided on the serialization
+path [#ogrisel-numpy]_.
+
+
 Caveats
 =======
 
@@ -479,6 +490,9 @@ References
 .. [#pickle5-pypi] ``pickle5`` project on PyPI
    https://pypi.org/project/pickle5/
 
+.. [#ogrisel-numpy] Draft use of pickle protocol 5 for Numpy array pickling
+   https://gist.github.com/ogrisel/a2b0e5ae4987a398caa7f9277cb3b90a
+
 
 Copyright
 =========