diff --git a/lib/spack/docs/spack.yaml b/lib/spack/docs/spack.yaml
index 2dd932b5658..778f0a3c753 100644
--- a/lib/spack/docs/spack.yaml
+++ b/lib/spack/docs/spack.yaml
@@ -20,6 +20,8 @@ spack:
   - py-docutils@:0.16
   - py-sphinx-design
   - py-sphinx-rtd-theme
+  - py-pygments@:2.12
+
   # VCS
   - git
   - mercurial