diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ce9dfc9..feb568d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        ruby-version: ['3.2', '3.3', '3.4']
+        ruby-version: ['3.4', '4.0']
 
     steps:
       - uses: actions/checkout@v3.5.2
diff --git a/miniproxy.gemspec b/miniproxy.gemspec
index 0b1381d..79911f6 100644
--- a/miniproxy.gemspec
+++ b/miniproxy.gemspec
@@ -14,7 +14,7 @@ Gem::Specification.new do |s|
 
   s.files = `git ls-files -- lib/* ssl/*`.split("\n")
 
-  s.required_ruby_version = Gem::Requirement.new('>= 3.2', '< 4')
+  s.required_ruby_version = Gem::Requirement.new('>= 3.4', '< 5')
 
   s.add_runtime_dependency 'webrick', '~> 1'
   s.add_runtime_dependency 'drb', '~> 2'