diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index de5589a..7ba5d4e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,7 +3,7 @@ jobs:
   test:
     strategy:
       matrix:
-        platform: [macos-latest, ubuntu-latest, windows-latest]
+        platform: [macos-latest, ubuntu-20.04, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps:
       - uses: actions/checkout@v3