diff --git a/build-constraints.yaml b/build-constraints.yaml
index de5719b3..33bb0dea 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4415,6 +4415,7 @@ packages:
 
     "Michael B. Gale <m.gale@warwick.ac.uk> @mbg":
         - c14n
+        - moss
         - wai-saml2
 
     "Jun Narumi <narumij@gmail.com> @narumij":