diff --git a/build-constraints.yaml b/build-constraints.yaml
index e215c567..008c85e9 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -2453,6 +2453,7 @@ packages:
 
     "Ashley Yakeley <ashley@semantic.org> @AshleyYakeley":
         - countable
+        - leapseconds
 
     "Victor Denisov <denisovenator@gmail.com> @VictorDenisov":
         - mongoDB