diff --git a/CHANGELOG.md b/CHANGELOG.md
index c32c379a..76b04737 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## 3.12.1 - 2018-04-05
+* [#636](https://github.com/stripe/stripe-ruby/pull/636) Fix a warning for uninitialized instance variable `@additive_params`
+
 ## 3.12.0 - 2018-04-05
 * [#632](https://github.com/stripe/stripe-ruby/pull/632) Introduce `additive_object_param` so that non-`metadata` subobjects don't zero their keys as they're being replaced
 
diff --git a/VERSION b/VERSION
index 92536a9e..171a6a93 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.12.0
+3.12.1
diff --git a/lib/stripe/version.rb b/lib/stripe/version.rb
index bfa4d3d8..183b4cdd 100644
--- a/lib/stripe/version.rb
+++ b/lib/stripe/version.rb
@@ -1,3 +1,3 @@
 module Stripe
-  VERSION = "3.12.0".freeze
+  VERSION = "3.12.1".freeze
 end