diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c6f7e44..c6b768c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -87,7 +87,7 @@ jobs:
               compiler: clang-12,  cxxstd: '03,11,14,17,20', os: ubuntu-20.04, stdlib: libc++, install: 'clang-12 libc++-12-dev libc++abi-12-dev' }
 
           # OSX, clang
-          - { compiler: clang,     cxxstd: '03,11,14,17,2a', os: macos-10.15, sanitize: yes }
+          - { compiler: clang,     cxxstd: '03,11,14,17,2a', os: macos-11, sanitize: yes }
 
           # Coverity Scan
           # requires two github secrets in repo to activate; see ci/github/coverity.sh