diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
deleted file mode 100644
index 2dbc56a36..000000000
--- a/.github/workflows/macos.yml
+++ /dev/null
@@ -1,22 +0,0 @@
-name: macos
-
-on: [push]
-
-jobs:
-  build:
-    runs-on: macos-latest
-    strategy:
-      matrix:
-        ruby: [ '2.6.x', '2.5.x', '2.4.x' ]
-    steps:
-    - uses: actions/checkout@master
-    - name: Set up Ruby
-      uses: actions/setup-ruby@v1
-      with:
-        ruby-version: ${{ matrix.ruby }}
-    - name: Install dependencies
-      run: gem install minitest
-    - name: Run test
-      env:
-        COVERALLS: "yes"
-      run: ruby -Ilib exe/rake
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/test.yml
similarity index 63%
rename from .github/workflows/ubuntu.yml
rename to .github/workflows/test.yml
index b67130ad8..d1f31e040 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/test.yml
@@ -4,14 +4,15 @@ on: [push]
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        ruby: [ '2.6.x', '2.5.x', '2.4.x' ]
+        os: [ 'ubuntu-latest', 'macos-latest', 'windows-latest' ]
+        ruby: [ 'head', '2.7', '2.6', '2.5', '2.4' ]
     steps:
     - uses: actions/checkout@master
     - name: Set up Ruby
-      uses: actions/setup-ruby@v1
+      uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
     - name: Install dependencies
diff --git a/.github/workflows/ubuntu-rvm.yml b/.github/workflows/ubuntu-rvm.yml
deleted file mode 100644
index cf3d1d05b..000000000
--- a/.github/workflows/ubuntu-rvm.yml
+++ /dev/null
@@ -1,28 +0,0 @@
-name: ubuntu-rvm
-
-on: [push]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        ruby: [ 'jruby-head', 'jruby-9.2.9.0', 'ruby-head', '2.3.8', '2.2.10' ]
-    steps:
-    - uses: actions/checkout@master
-    - name: Set up RVM
-      run: |
-        curl -sSL https://get.rvm.io | bash
-    - name: Set up Ruby
-      run: |
-        source $HOME/.rvm/scripts/rvm
-        rvm install ${{ matrix.ruby }} --binary
-        rvm --default use ${{ matrix.ruby }}
-    - name: Install dependencies
-      run: |
-        source $HOME/.rvm/scripts/rvm
-        gem install minitest
-    - name: Run test
-      run: |
-        source $HOME/.rvm/scripts/rvm
-        ruby -Ilib exe/rake
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
deleted file mode 100644
index 5ced11c45..000000000
--- a/.github/workflows/windows.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-name: windows
-
-on: [push]
-
-jobs:
-  build:
-    runs-on: windows-latest
-    strategy:
-      matrix:
-        ruby: [ '2.6.x', '2.5.x', '2.4.x' ]
-    steps:
-    - uses: actions/checkout@master
-    - name: Set up Ruby
-      uses: actions/setup-ruby@v1
-      with:
-        ruby-version: ${{ matrix.ruby }}
-    - name: Install dependencies
-      run: gem install minitest
-    - name: Run test
-      run: ruby -Ilib exe/rake