diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 08907fd3d..91dbdadf0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -279,7 +279,7 @@ jobs:
             compiler-name: Clang LLVM
             os-name: macOS
             os-arch: x86_64
-            os: macos-latest
+            os: macos-10.15
             cmake-gen: Ninja
     name: |
       ${{ matrix.os-name }}