diff --git a/CHANGELOG.md b/CHANGELOG.md
index 565a495d..6a3ea653 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,14 @@
-# Unreleased
-
-- Update rubocop to 1.7.0
+# 4.0.0.pre-1
+
+- Released as a pre-release to try surface any issues before wider rollout,
+  use https://github.com/alphagov/rubocop-govuk/issues/129 to record any
+  problems
+- BREAKING: Upgraded from Rubocop 0.x to 1.x which introduces lots of new
+  cops
+- Update rubocop to 1.10.0
 - Update rubocop-ast to 1.4.0
 - Update rubocop-rails to 2.9.1
-- Update rubocop-rspec to 2.1.0
+- Update rubocop-rspec to 2.2.0
 - Make stable dependencies (>= 1.0) less strict on patch version
 - Disable `SuggestExtensions` to stop Rubocop suggesting additional
   extensions at runtime
diff --git a/rubocop-govuk.gemspec b/rubocop-govuk.gemspec
index 5049bc0b..84ad3079 100644
--- a/rubocop-govuk.gemspec
+++ b/rubocop-govuk.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |spec|
   spec.name          = "rubocop-govuk"
-  spec.version       = "3.17.2"
+  spec.version       = "4.0.0.pre-1"
   spec.authors       = ["Government Digital Service"]
   spec.email         = ["govuk-dev@digital.cabinet-office.gov.uk"]