diff --git a/CHANGES.txt b/CHANGES.txt
index deedef0..d3a9b7e 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,6 @@
+## v0.3.1 - 11 Apr 2021
+* temporarily keep backward compatibility wrt top-level module names
+
 ## v0.3.0 - 10 Apr 2021
 * build: switch to dune, dune-configurator and ppxlib
 * sockopt: handle missing options at runtime
diff --git a/Makefile b/Makefile
index d685b76..0b03917 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ doc:
 test:
 	dune runtest
 
-VERSION=0.3.0
+VERSION=0.3.1
 NAME=ocaml-extunix-$(VERSION)
 
 release:
diff --git a/README.md b/README.md
index e72cd55..210fd87 100644
--- a/README.md
+++ b/README.md
@@ -136,6 +136,7 @@ Checklist for release
 ---------------------
 
 * Review `git log` and update [`CHANGES.txt`][]
+* Increase VERSION in Makefile
 * Commit
 * `make release`