diff --git a/build-constraints.yaml b/build-constraints.yaml
index abfed8b6..10517ae7 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1740,6 +1740,7 @@ packages:
     "Dennis Gosnell <cdep.illabout@gmail.com> @cdepillabout":
         - emailaddress
         - envelope
+        - hailgun
         # GHC 8 - ig
         - natural-transformation
         - opaleye-trans