diff --git a/pyproject.toml b/pyproject.toml
index 931362d..4a7d46d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,6 @@
 [build-system]
 requires = [
+    # When dropping Python2.7, revert to "hatchling>=0.22.0"
     "hatchling==0.22.0",
 ]
 build-backend = "hatchling.build"