diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 0473018..27eb424 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -20,9 +20,9 @@ jobs:
         # x86_64 + arm64. macOS x86_64 runs in `test-macos-intel` below.
         os: [ macos-26 ]
         include:
-          - os: ubuntu-latest
+          - os: ubuntu-26.04
             container: ghcr.io/homebrew/brew:main
-          - os: ubuntu-24.04-arm
+          - os: ubuntu-26.04-arm
             container: ghcr.io/homebrew/brew:main
     runs-on: ${{ matrix.os }}
     container: ${{ matrix.container }}
@@ -75,7 +75,7 @@ jobs:
     needs:
       - test-bot
       - test-macos-intel
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     steps:
       - name: Verify all jobs succeeded
         uses: Mergifyio/gha-mergify-ci@5e8176734bc525c7fd8b2e812f0fa47246f601b7 # v25