diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index bb6e68b..6ea3c10 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -387,6 +387,11 @@
 :func:`call` and :meth:`Popen.communicate` will raise :exc:`TimeoutExpired` if
 the timeout expires before the process exits.
 
+Exceptions defined in this module all inherit from :ext:`SubprocessError`.
+
+   .. versionadded:: 3.3
+      The :exc:`SubprocessError` base class was added.
+
 
 Security
 ^^^^^^^^