diff --git a/CHANGELOG.md b/CHANGELOG.md
index af2b5e3..a60634e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 See this http://keepachangelog.com link for information on how we want this documented formatted.
 
+## v5.2.2
+
+- Lock down to Rack < 3 in 5-stable branch.
+
 ## v5.2.1
 
 - Rack 3.X compatibility, by removing uninitialized constants.
diff --git a/Gemfile.lock b/Gemfile.lock
index 4a85ddd..3dcfe4f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,9 +1,9 @@
 PATH
   remote: .
   specs:
-    lamby (5.2.1)
+    lamby (5.2.2)
       lambda-console-ruby
-      rack
+      rack (< 3)
 
 GEM
   remote: https://rubygems.org/
diff --git a/lamby.gemspec b/lamby.gemspec
index 77ac617..8ba2160 100644
--- a/lamby.gemspec
+++ b/lamby.gemspec
@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-  spec.add_dependency 'rack'
+  spec.add_dependency 'rack', '< 3'
   spec.add_dependency 'lambda-console-ruby'
   spec.add_development_dependency 'aws-sdk-ssm'
   spec.add_development_dependency 'bundler'
diff --git a/lib/lamby/version.rb b/lib/lamby/version.rb
index b67f254..a14acea 100644
--- a/lib/lamby/version.rb
+++ b/lib/lamby/version.rb
@@ -1,3 +1,3 @@
 module Lamby
-  VERSION = '5.2.1'
+  VERSION = '5.2.2'
 end
diff --git a/vendor/.keep b/vendor/.keep
deleted file mode 100644
index e69de29..0000000