diff --git a/.github/workflows/cmake.yml b/.github/workflows/cmake.yml
index 6665cdea..57e99443 100644
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -13,7 +13,7 @@ jobs:
       # Don't cancel the macOS build if the Linux build fails, etc.
       fail-fast: false
       matrix:
-        os: [ubuntu-18.04, macos-10.15]
+        os: [ubuntu-20.04, macos-10.15]
 
     steps:
     - uses: actions/checkout@v2