diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4161ee5..c573189 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -34,6 +34,7 @@ jobs:
       spack-manifest-path: ${{ matrix.file }}
       allow-ssh-into-spack-install: false  # If true, PR author must ssh into instance to complete job
       spack-manifest-data-path: .github/build-ci/data/standard.json
+      container-image-version: :rocky-v1.1-2026.05.001
       # builtin-spack-packages-ref: main
       # access-spack-packages-ref: api-v2
       # spack-config-ref: main