diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 213a87ba1..ee36833ca 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -42,16 +42,17 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
-      # We need "pip cache dir", which became a thing in pip v20.1+.
-      # At the time of writing this, GitHub Actions offers pip v20.3.3
-      # for both ubuntu-latest and windows-latest, and pip v20.3.1 for
-      # macos-latest.  Those are sufficiently recent pip versions that
-      # have "cache dir" sub-command.
+      # To use pip caching with GitHub Actions in an OS-independent
+      # manner, we need `pip cache dir` command, which became
+      # available since pip v20.1+.  At the time of writing this,
+      # GitHub Actions offers pip v20.3.3 for both ubuntu-latest and
+      # windows-latest, and pip v20.3.1 for macos-latest.
       - name: Get pip cache directory
         id: pip-cache
         run: |
           echo "::set-output name=dir::$(pip cache dir)"
 
+      # See https://github.com/actions/cache
       - name: Use pip cache
         uses: actions/cache@v2
         with: