diff --git a/.travis.yml b/.travis.yml
index af35980111..59893c7957 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,7 +11,7 @@ branches:
   only:
     - "master"
 rvm:
-  - 2.2.8
+  - 2.2.9
   - 2.3.6
   - 2.4.3
   - 2.5.0
diff --git a/Gemfile b/Gemfile
index 59e3bf8dba..8dc1f79b72 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,6 +13,6 @@ gem "jruby-openssl", :platform => "jruby"
 
 gem "rubocop", "~> 0.50.0"
 
-if %w(2.2.7 2.2.8 2.3.4 2.4.1).include? RUBY_VERSION
+if %w(2.2.7 2.2.8 2.2.9 2.3.4 2.4.1).include? RUBY_VERSION
   gem "stopgap_13632", "~> 1.0", :platforms => ["mri", "mingw", "x64_mingw"]
 end
diff --git a/README.md b/README.md
index 1d7a8e8a75..6c1d0ac4e3 100644
--- a/README.md
+++ b/README.md
@@ -217,10 +217,10 @@ Some platforms do not support all Puma features.
 
 ## Known Bugs
 
-For MRI versions 2.2.7, 2.2.8, 2.3.4 and 2.4.1, you may see ```stream closed in another thread (IOError)```. It may be caused by a [Ruby bug](https://bugs.ruby-lang.org/issues/13632). It can be fixed with the gem https://rubygems.org/gems/stopgap_13632:
+For MRI versions 2.2.7, 2.2.8, 2.2.9, 2.3.4 and 2.4.1, you may see ```stream closed in another thread (IOError)```. It may be caused by a [Ruby bug](https://bugs.ruby-lang.org/issues/13632). It can be fixed with the gem https://rubygems.org/gems/stopgap_13632:
 
 ```ruby
-if %w(2.2.7 2.2.8 2.3.4 2.4.1).include? RUBY_VERSION
+if %w(2.2.7 2.2.8 2.2.9 2.3.4 2.4.1).include? RUBY_VERSION
   begin
     require 'stopgap_13632'
   rescue LoadError
diff --git a/test/helper.rb b/test/helper.rb
index d230c60be0..d0fe7816a9 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -1,7 +1,7 @@
 # Copyright (c) 2011 Evan Phoenix
 # Copyright (c) 2005 Zed A. Shaw
 
-if %w(2.2.7 2.2.8 2.3.4 2.4.1).include? RUBY_VERSION
+if %w(2.2.7 2.2.8 2.2.9 2.3.4 2.4.1).include? RUBY_VERSION
   begin
     require 'stopgap_13632'
   rescue LoadError