diff --git a/CHANGELOG.md b/CHANGELOG.md
index 481b5cf..e657a5e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [0.5.0] - 2019-10-09
+
+- Crystal 0.31.0 changed the behaviour of `Int#/` in favour of `Int#//` for integer division. This affected the base32 module, which no longer builds. Updated to point at a fork of base32 that does build in 0.31.0.
+
 ## [0.4.0] - 2019-08-18
 
 ### Changed
diff --git a/shard.yml b/shard.yml
index 89bbb76..9c7bc13 100644
--- a/shard.yml
+++ b/shard.yml
@@ -1,5 +1,5 @@
 name: crotp
-version: 0.4.0
+version: 0.5.0
 
 authors:
   - Phil Nash <philnash@gmail.com>
@@ -9,6 +9,6 @@ dependencies:
     github: repomaa/base32
     branch: topic/crystal-0-31-0
 
-crystal: 0.30.0
+crystal: 0.31.0
 
 license: MIT