diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
index ff820fa98c..2125d498c6 100644
--- a/.github/workflows/check_dependencies.yml
+++ b/.github/workflows/check_dependencies.yml
@@ -15,7 +15,7 @@ jobs:
   update-deps:
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-11]
+        os: [ubuntu-20.04]
       fail-fast: true
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
deleted file mode 100644
index ab6f47bd26..0000000000
--- a/.github/workflows/macos.yml
+++ /dev/null
@@ -1,79 +0,0 @@
-name: macOS
-on:
-  push:
-    paths-ignore:
-      - 'doc/**'
-      - '**.md'
-      - '**.rdoc'
-  pull_request:
-    paths-ignore:
-      - 'doc/**'
-      - '**.md'
-      - '**.rdoc'
-
-jobs:
-  make:
-    strategy:
-      matrix:
-        os: [macos-10.15, macos-11]
-        test_task: [ "check", "test-bundler-parallel" ] #, "test-bundled-gems" ] matrix tests has unknown issues
-      fail-fast: false
-    env:
-      RUBY_TESTOPTS: '-q --tty=no'
-      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
-    runs-on: ${{ matrix.os }}
-    steps:
-      - run: mkdir build
-        working-directory:
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@v2
-        with:
-          path: src
-      - name: Install libraries
-        run: |
-          brew upgrade
-          brew install gmp libffi openssl@1.1 zlib autoconf automake libtool readline
-        working-directory: src
-      - name: Set ENV
-        run: |
-          echo "MAKEFLAGS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
-      - run: ./autogen.sh
-        working-directory: src
-      - name: Run configure
-        run: ../src/configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
-      - run: make incs
-      - run: make
-      - run: make leaked-globals
-        if: ${{ matrix.test_task == 'check' }}
-      - run: make prepare-gems
-        if: ${{ matrix.test_task == 'check' }}
-      - run: make -s ${{ matrix.test_task }}
-        timeout-minutes: 40
-        env:
-          TEST_BUNDLED_GEMS_ALLOW_FAILURES: "rexml"
-      - run: make -s check RUN_OPTS="--yjit"
-        timeout-minutes: 60
-        if: ${{ matrix.test_task == 'check' }}
-      - run: make -s check RUN_OPTS="--yjit --yjit-call-threshold=1 --yjit-max-versions=1"
-        timeout-minutes: 60
-        if: ${{ matrix.test_task == 'check' }}
-      - uses: k0kubun/action-slack@v2.0.0
-        with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / ${{ matrix.test_task }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref }}".split('/').reverse()[0]
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
-
-defaults:
-  run:
-    working-directory: build