diff --git a/build-constraints.yaml b/build-constraints.yaml
index ab5a5865..17ed114b 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -2499,6 +2499,7 @@ packages:
 
     "Ashley Yakeley <ashley@semantic.org> @AshleyYakeley":
         - countable
+        - leapseconds
 
     "Victor Denisov <denisovenator@gmail.com> @VictorDenisov":
         - mongoDB