diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c7bca49..7be7670 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -14,6 +14,12 @@ jobs:
         os: [windows-latest, macos-10.15, ubuntu-18.04]
 
     steps:
+    - name: configure
+      run: |
+         if [ "$RUNNER_OS" == "Linux" ]; then
+          export CXX=g++-9
+         fi
+      shell: bash
     - uses: actions/checkout@v2
     - name: Build
       run: cmake -S. -Bbin && cmake --build bin --config $BUILD_TYPE