diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 1afc84c3f3a4bb..b91361e0c59cbd 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -38,12 +38,6 @@ jobs:
             os: macos-12
           - test_task: check
             os: macos-13
-
-          - test_task: check
-            gc_name: 'default'
-            shared_gc: true
-            configure: '--with-shared-gc=/Users/runner/ruby_gc'
-            os: macos-14
           - test_task: check
             gc_name: 'mmtk'
             build: 'debug'
@@ -107,7 +101,9 @@ jobs:
         continue-on-error: true
 
       - name: Run configure
-        run: ../src/configure -C --disable-install-doc ${ruby_configure_args}
+        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
@@ -119,7 +115,7 @@ jobs:
 
       - name: Build shared GC
         run: |
-          echo "RUBY_GC_LIBRARY=librubygc.${{ matrix.gc_name }}.so" >> $GITHUB_ENV
+          echo "RUBY_GC_LIBRARY=librubygc.${{ matrix.gc_name }}.dylib" >> $GITHUB_ENV
           make shared-gc SHARED_GC=${{ matrix.gc_name }} MMTK_BUILD=${{ matrix.build }}
         if: ${{ matrix.shared_gc }}
 
@@ -168,19 +164,6 @@ jobs:
           ulimit -c unlimited
           make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"}
         timeout-minutes: 60
-        if: ${{ !matrix.shared_gc }}
-        env:
-          RUBY_TESTOPTS: '-q --tty=no'
-          TEST_BUNDLED_GEMS_ALLOW_FAILURES: 'typeprof'
-          PRECHECK_BUNDLED_GEMS: 'no'
-
-      - name: make ${{ matrix.test_task }}
-        run: >-
-          $SETARCH make -s ${{ matrix.test_task }}
-          ${TESTS:+TESTS="$TESTS"}
-          ${{ !contains(matrix.test_task, 'bundle') && 'RUBYOPT=-w' || '' }}
-        timeout-minutes: ${{ matrix.timeout || 40 }}
-        if: ${{ matrix.shared_gc}}
         env:
           RUBY_TESTOPTS: '-q --tty=no'
           TEST_BUNDLED_GEMS_ALLOW_FAILURES: 'typeprof'