diff --git a/requirements/constraints.txt b/requirements/constraints.txt
index e824313..3351b3d 100644
--- a/requirements/constraints.txt
+++ b/requirements/constraints.txt
@@ -12,4 +12,5 @@
 # Common constraints for edx repos
 -c common_constraints.txt
 
+# its not required on python 3.9
 backports.zoneinfo;python_version<"3.9"
\ No newline at end of file