diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a40d2fd5d..b1e1bacb6 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -13,7 +13,7 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - name: (Linux) Download LLVM
-        run: sudo apt-get install -y llvm-10 llvm-10-dev
+        run: sudo apt-get install llvm-9 llvm-9-dev
       - name: Build
         run: |
           mkdir build && cd build