diff --git a/.github/workflows/on_pull_request.yml b/.github/workflows/on_pull_request.yml
index c733161..c73111a 100644
--- a/.github/workflows/on_pull_request.yml
+++ b/.github/workflows/on_pull_request.yml
@@ -106,7 +106,7 @@ jobs:
       - uses: actions/checkout@v2
       - name: Install Dependencies
         run: |
-          sudo apt install -y clang lld
+          sudo apt install -y clang lld "libc++"
       - name: Configure
         run: |
           set -x
@@ -114,6 +114,8 @@ jobs:
           cd Clang
           export CC=$(which clang)
           export CXX=$(which clang++)
+          export CXXFLAGS=$(-stdlib=libc++)
+          export LDFLAGS=$(-stdlib=libc++)
           cmake -DCMAKE_CXX_STANDARD=20 ..
       - name: Build
         run: |