diff --git a/.github/workflows/actions.yml b/.github/workflows/actions.yml
index 049bb03..63f0a6d 100644
--- a/.github/workflows/actions.yml
+++ b/.github/workflows/actions.yml
@@ -30,6 +30,11 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: true
+      - name: 'setup'
+        if: contains(matrix.vm_image, '20.04')
+        run: |
+          sudo apt-get install -y g++-10
+          sudo update-alternatives -install /usr/bin/g++ g++ /usr/bin/g++-10 100
       - name: 'configure'
         run: |
           cmake -DCMAKE_BUILD_TYPE=${{ matrix.config.mode }} -Bbuild -S.