diff --git a/peps/pep-0440.rst b/peps/pep-0440.rst
index 86a82ea1e5e..c098ddafa43 100644
--- a/peps/pep-0440.rst
+++ b/peps/pep-0440.rst
@@ -1623,7 +1623,7 @@ project)::
             (?P<release>[0-9]+(?:\.[0-9]+)*)                  # release segment
             (?P<pre>                                          # pre-release
                 [-_\.]?
-                (?P<pre_l>(a|b|c|rc|alpha|beta|pre|preview))
+                (?P<pre_l>alpha|a|beta|b|preview|pre|c|rc)
                 [-_\.]?
                 (?P<pre_n>[0-9]+)?
             )?