diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 68738e7..a33aa0c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,7 +18,8 @@ jobs:
           ./scripts/lint-newsletters.sh
 
   test:
-    runs-on: ubuntu-latest
+    # ubuntu-latest moved to Ubuntu 26.04, which has no Python 3.8 or 3.9 builds.
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11"]