diff --git a/.github/workflows/sharedgc-macos.yml b/.github/workflows/sharedgc-macos.yml
deleted file mode 100644
index 80daf65e863333..00000000000000
--- a/.github/workflows/sharedgc-macos.yml
+++ /dev/null
@@ -1,212 +0,0 @@
-name: Shared GC (macOS)
-on:
-  push:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man/*'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-      - '.*.yml'
-  pull_request:
-    # Do not use paths-ignore for required status checks
-    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
-  merge_group:
-
-concurrency:
-  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
-  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
-
-permissions:
-  contents: read
-
-jobs:
-  make:
-    strategy:
-      matrix:
-        include:
-          - test_task: check
-            gc_name: 'mmtk'
-            build: 'debug'
-            configure: '--with-shared-gc=/Users/runner/ruby_gc'
-            os: macos-14
-          - test_task: check
-            gc_name: 'mmtk'
-            build: 'release'
-            configure: '--with-shared-gc=/Users/runner/ruby_gc'
-            os: macos-14
-      fail-fast: false
-
-    env:
-      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
-
-    runs-on: ${{ matrix.os }}
-
-    if: >-
-      ${{!(false
-      || contains(github.event.head_commit.message, '[DOC]')
-      || contains(github.event.head_commit.message, 'Document')
-      || contains(github.event.pull_request.title, '[DOC]')
-      || contains(github.event.pull_request.title, 'Document')
-      || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.event.pull_request.user.login == 'dependabot[bot]')
-      )}}
-
-    steps:
-      - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938 # v4.2.0
-        with:
-          sparse-checkout-cone-mode: false
-          sparse-checkout: /.github
-
-      - name: Install libraries
-        uses: ./.github/actions/setup/macos
-
-      - uses: ./.github/actions/setup/directories
-        with:
-          srcdir: src
-          builddir: build
-          makeup: true
-          clean: true
-          dummy-files: ${{ matrix.test_task == 'check' }}
-          # Set fetch-depth: 0 so that Launchable can receive commits information.
-          fetch-depth: 10
-
-      - name: make sure that kern.coredump=1
-        run: |
-          sysctl -n kern.coredump
-          sudo sysctl -w kern.coredump=1
-          sudo chmod -R +rwx /cores/
-
-      - name: Delete unused SDKs
-        # To free up disk space to not run out during the run
-        run: |
-          sudo rm -rf ~/.dotnet
-          sudo rm -rf /Library/Android
-          sudo rm -rf /Library/Developer/CoreSimulator
-        continue-on-error: true
-
-      - name: Run configure
-        env:
-          configure: ${{ matrix.configure }} ${ruby_configure_args}
-        run: ../src/configure -C --disable-install-doc ${{ env.configure }}
-
-      - uses: actions-rust-lang/setup-rust-toolchain@v1
-      - name: Build MMTK Ruby lib
-        run: |
-          cd ../src/gc/mmtk
-          cargo build ${{ matrix.build != 'debug' && format('--{0}', matrix.build) || format('') }}
-          echo "RUST_LOG=" >> $GITHUB_ENV
-          echo "EXCLUDES=../src/test/.excludes-mmtk" >> $GITHUB_ENV
-        if: ${{ matrix.gc_name == 'mmtk' }}
-
-      - name: Build shared GC
-        run: |
-          echo "RUBY_GC_LIBRARY=${{ matrix.gc_name }}" >> $GITHUB_ENV
-          make shared-gc SHARED_GC=${{ matrix.gc_name }} MMTK_BUILD=${{ matrix.build }}
-
-      - name: Verify MMTk bindgen
-        run: |
-          cd ../src/gc/mmtk
-          cargo install --force cbindgen@0.26.0
-          cbindgen --config cbindgen.toml --output ../mmtk.h
-          if read -n1 -d '' < <(git diff ../mmtk.h); then
-            git diff ../mmtk.h
-            exit 1
-          fi
-        if: ${{ matrix.gc_name == 'mmtk' }}
-
-      - run: make prepare-gems
-        if: ${{ matrix.test_task == 'test-bundled-gems' }}
-
-      - run: make
-
-      - run: |
-          make golf
-          case "${{ matrix.configure }}" in
-          *'--enable-shared'*)
-            make runnable
-            ./bin/goruby -veh
-            ;;
-          *)
-            ./goruby -veh
-            ;;
-          esac
-
-      - name: Set test options for skipped tests
-        run: |
-          set -x
-          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
-          echo "TESTS=${TESTS}" >> $GITHUB_ENV
-        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
-
-      - name: Set up Launchable
-        uses: ./.github/actions/launchable/setup
-        with:
-          os: ${{ matrix.os }}
-          test-opts: ${{ matrix.test_opts }}
-          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
-          builddir: build
-          srcdir: src
-        continue-on-error: true
-
-      - name: Set extra test options
-        run: |
-          echo "TESTS=$TESTS ${{ matrix.test_opts }}" >> $GITHUB_ENV
-          echo "RUBY_TEST_TIMEOUT_SCALE=10" >> $GITHUB_ENV # With --repeat-count=2, flaky test by timeout occurs frequently for some reason
-        if: matrix.test_opts
-
-      - name: make ${{ matrix.test_task }}
-        run: |
-          ulimit -c unlimited
-          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"}
-        timeout-minutes: 60
-        env:
-          RUBY_TESTOPTS: '-q --tty=no'
-          TEST_BUNDLED_GEMS_ALLOW_FAILURES: 'typeprof'
-          PRECHECK_BUNDLED_GEMS: 'no'
-
-      - name: make skipped tests
-        run: |
-          make -s test-all TESTS="${TESTS//-n!\//-n/}"
-        env:
-          GNUMAKEFLAGS: ''
-          RUBY_TESTOPTS: '-v --tty=no'
-          PRECHECK_BUNDLED_GEMS: 'no'
-        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
-        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
-
-      - uses: ./.github/actions/slack
-        with:
-          label: ${{ matrix.os }} / ${{ matrix.test_task }}
-          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() }}
-
-      - name: Resolve job ID
-        id: job_id
-        uses: actions/github-script@main
-        env:
-          matrix: ${{ toJson(matrix) }}
-        with:
-          script: |
-            const { data: workflow_run } = await github.rest.actions.listJobsForWorkflowRun({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              run_id: context.runId
-            });
-            const matrix = JSON.parse(process.env.matrix);
-            const job_name = `${context.job}${matrix ? ` (${Object.values(matrix).join(", ")})` : ""}`;
-            return workflow_run.jobs.find((job) => job.name === job_name).id;
-
-  result:
-    if: ${{ always() }}
-    name: ${{ github.workflow }} result
-    runs-on: macos-latest
-    needs: [make]
-    steps:
-      - run: exit 1
-        working-directory:
-        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
-
-defaults:
-  run:
-    working-directory: build
diff --git a/.github/workflows/sharedgc-ubuntu.yml b/.github/workflows/sharedgc.yml
similarity index 85%
rename from .github/workflows/sharedgc-ubuntu.yml
rename to .github/workflows/sharedgc.yml
index 181044d880e49c..b48f4a76111b94 100644
--- a/.github/workflows/sharedgc-ubuntu.yml
+++ b/.github/workflows/sharedgc.yml
@@ -24,6 +24,7 @@ jobs:
   make:
     strategy:
       matrix:
+        os: [macos-latest, ubuntu-latest]
         gc_name: ['default', 'mmtk']
         build: ['debug', 'release']
         mmtk_plan: ['MarkSweep', 'Immix']
@@ -43,7 +44,7 @@ jobs:
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
       RUBY_DEBUG: ci
 
-    runs-on: ${{ matrix.os || 'ubuntu-22.04' }}
+    runs-on: ${{ matrix.os }}
 
     if: >-
       ${{!(false
@@ -61,14 +62,19 @@ jobs:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
 
-      - uses: ./.github/actions/setup/ubuntu
-        with:
-          arch: ${{ matrix.arch }}
+      - name: Install libraries (macOS)
+        uses: ./.github/actions/setup/macos
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Install libraries (Ubuntu)
+        uses: ./.github/actions/setup/ubuntu
+        if: ${{ contains(matrix.os, 'ubuntu') }}
 
       - uses: ruby/setup-ruby@a6e6f86333f0a2523ece813039b8b4be04560854 # v1.190.0
         with:
           ruby-version: '3.0'
           bundler: none
+        if: ${{ contains(matrix.os, 'ubuntu') }}
 
       - uses: ./.github/actions/setup/directories
         with:
@@ -80,10 +86,25 @@ jobs:
           # Set fetch-depth: 10 so that Launchable can receive commits information.
           fetch-depth: 10
 
+      - name: make sure that kern.coredump=1
+        run: |
+          sysctl -n kern.coredump
+          sudo sysctl -w kern.coredump=1
+          sudo chmod -R +rwx /cores/
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Delete unused SDKs
+        # To free up disk space to not run out during the run
+        run: |
+          sudo rm -rf ~/.dotnet
+          sudo rm -rf /Library/Android
+          sudo rm -rf /Library/Developer/CoreSimulator
+        continue-on-error: true
+        if: ${{ contains(matrix.os, 'macos') }}
+
       - name: Run configure
         env:
-          arch: ${{ matrix.arch }}
-          configure: ${{ matrix.configure }}
+          configure: ${{ matrix.configure }} ${ruby_configure_args}
         run: >-
           $SETARCH ../src/configure -C --disable-install-doc ${configure:-cppflags=-DRUBY_DEBUG}
           ${arch:+--target=$arch-$OSTYPE --host=$arch-$OSTYPE}