diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index d3ac3c4..60614f8 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.5', '2.7', '3.1', '3.2', '3.3']
+        ruby-version: ['2.5', '2.7', '3.1', '3.2', '3.3', '3.4']
 
     steps:
     - uses: actions/checkout@v4
diff --git a/cf-uaa-lib.gemspec b/cf-uaa-lib.gemspec
index 54c58ac..3763e65 100644
--- a/cf-uaa-lib.gemspec
+++ b/cf-uaa-lib.gemspec
@@ -32,6 +32,8 @@ Gem::Specification.new do |s|
 
   # dependencies
   s.add_dependency 'json', '~>2.7'
+  s.add_dependency 'mutex_m'
+  s.add_dependency 'base64'
   s.add_dependency 'httpclient', '~> 2.8', '>= 2.8.2.4'
   s.add_dependency 'addressable', '~> 2.8', '>= 2.8.0'
 
diff --git a/lib/uaa/http.rb b/lib/uaa/http.rb
index 8972ad0..f89ac8c 100644
--- a/lib/uaa/http.rb
+++ b/lib/uaa/http.rb
@@ -11,6 +11,7 @@
 # subcomponent's license, as noted in the LICENSE file.
 #++
 
+require 'mutex_m'
 require 'base64'
 require 'uaa/util'
 require 'httpclient'