diff --git a/ci/upstream.yml b/ci/upstream.yml
index 702ac093..cac1100c 100644
--- a/ci/upstream.yml
+++ b/ci/upstream.yml
@@ -24,7 +24,7 @@ dependencies:
   - fsspec
   - pip
   - pip:
-    - zarr==3.0.0b1
-    - git+https://github.com/pydata/xarray@zarr-v3
-    - git+https://github.com/zarr-developers/numcodecs@zarr3-codecs
+    - zarr==3.0.0b1  # beta release of zarr-python v3
+    - git+https://github.com/pydata/xarray@zarr-v3  # zarr-v3 compatibility branch 
+    - git+https://github.com/zarr-developers/numcodecs@zarr3-codecs  # zarr-v3 compatibility branch 
     # - git+https://github.com/fsspec/kerchunk@main  # kerchunk is currently incompatible with zarr-python v3 (https://github.com/fsspec/kerchunk/pull/516)