diff --git a/build-constraints.yaml b/build-constraints.yaml
index d6db34a5..119df069 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -194,6 +194,7 @@ packages:
         - bake
         - ghcid
         - pugixml
+        - hexml
 
     "Alan Zimmerman @alanz":
         - hjsmin