diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 99e82963..00c4cec1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,7 +6,7 @@ on:
   pull_request:
 jobs:
   rubocop:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - name: Checkout
         uses: actions/checkout@v3
@@ -20,9 +20,9 @@ jobs:
   build:
     strategy:
       matrix:
-        ruby: [ 'jruby-9.2', '2.3', '3.0' ]
-        python: [ '3.5', '3.10' ]
-        platform: [ ubuntu-latest, macos-latest, windows-latest ]
+        ruby: [ 'jruby-9.2', '2.3', '3.1' ]
+        python: [ '3.6', '3.11' ]
+        platform: [ ubuntu-18.04, macos-latest, windows-2019 ]
     runs-on: ${{ matrix.platform }}
     steps:
       - name: Checkout
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 3369be41..a636fa94 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -4,18 +4,18 @@ on:
     tags: [ '*' ]
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v3
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.0'
+          ruby-version: '3.1'
           bundler-cache: true
       - name: Setup Python
         uses: actions/setup-python@v4
         with:
-          python-version: '3.9'
+          python-version: '3.11'
       - name: Build
         run: bundle exec rake build
       - name: Publish to RubyGems.org
diff --git a/README.adoc b/README.adoc
index b607a67a..059283b2 100644
--- a/README.adoc
+++ b/README.adoc
@@ -22,7 +22,7 @@ If a Python process dies, a new one will be spawned on the next pygments.rb requ
 
 == System Requirements
 
-- Python >= 3.5
+- Python >= 3.6
 - Ruby >= 2.3
 
 == Installation