diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8bfbf5f4..eb62f517 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -46,7 +46,6 @@ jobs:
       matrix:
         include:
           # NB: Sync list with https://github.com/taiki-e/checkout-action/blob/HEAD/.github/workflows/ci.yml
-          - os: ubuntu-20.04
           - os: ubuntu-22.04
           - os: ubuntu-24.04
           - os: ubuntu-22.04