diff --git a/.github/workflows/build_macos.yml b/.github/workflows/build_macos.yml
index 79ec23ea..1d5ee055 100644
--- a/.github/workflows/build_macos.yml
+++ b/.github/workflows/build_macos.yml
@@ -3,7 +3,7 @@ on: [push, pull_request]
 
 jobs:
   build:
-    runs-on: macos-latest
+    runs-on: macos-11
     steps:
       - name: Check out code
         uses: actions/checkout@v2