diff --git a/CHANGES.rst b/CHANGES.rst
index 2dcffe023c..6021a5640b 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -15,6 +15,9 @@ Unreleased
     screen. Refs :issue:`2911` :pr:`3004`
 -   Fix completion for the Z shell (``zsh``) for completion items containing
     colons. :issue:`2703` :pr:`2846`
+-   Fix a rare race in ``click.testing.StreamMixer``'s finalization that manifested
+    as a ``ValueError`` on close in a multi-threaded test session.
+    :issue:`2993` :pr:`2991`
 
 Version 8.2.1
 -------------