diff --git a/share/spack/gitlab/cloud_pipelines/stacks/hep/spack.yaml b/share/spack/gitlab/cloud_pipelines/stacks/hep/spack.yaml
index 3027875ed7b..6429d6937d9 100644
--- a/share/spack/gitlab/cloud_pipelines/stacks/hep/spack.yaml
+++ b/share/spack/gitlab/cloud_pipelines/stacks/hep/spack.yaml
@@ -88,7 +88,7 @@ spack:
   - pandorasdk
   - photos +hepmc3
   - podio +rntuple +sio
-  #- professor
+  - professor
   - py-awkward
   - py-boost-histogram
   - py-hepunits