diff --git a/CHANGES.md b/CHANGES.md
index 52c8016a257..e9742c666cf 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -12,6 +12,8 @@
 
 - fixed a crash when PWD=/ on POSIX (#1631)
 
+- fixed "I/O operation on closed file" on non-Windows OS when using --diff (#1664)
+
 - Prevent coloured diff output being interleaved with multiple files (#1673)
 
 ### 20.8b1
diff --git a/README.md b/README.md
index 20f6fa420b2..be66328c775 100644
--- a/README.md
+++ b/README.md
@@ -635,6 +635,7 @@ Multiple contributions by:
 - [Paul Ganssle](mailto:p.ganssle@gmail.com)
 - [Paul Meinhardt](mailto:mnhrdt@gmail.com)
 - [Peter Bengtsson](mailto:mail@peterbe.com)
+- [Peter Grayson](mailto:pete@jpgrayson.net)
 - [Peter Stensmyr](mailto:peter.stensmyr@gmail.com)
 - pmacosta
 - [Quentin Pradet](mailto:quentin@pradet.me)