diff --git a/spack.yaml b/spack.yaml
index 068bc26..7470059 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -8,7 +8,8 @@ spack:
   packages:
     # Direct ACCESS-NRI dependencies
     # Note: some packages have branch-specific logic and hence can't use
-    # the usual '@git.DATE' calver (https://calver.org) format.
+    # the usual '@git.DATE' calver (https://calver.org) format, instead
+    # requiring a `@git.DATE=BRANCH` version.
     mom5:
       require:
         - '@git.access-esm1.5_2024.06.20=access-esm1.5'