diff --git a/build-constraints.yaml b/build-constraints.yaml
index 35d6beec..2bbdd3e2 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -283,7 +283,7 @@ packages:
         - lazyio
         - markov-chain
         - midi
-        # - midi-music-box # lens 4.16 via diagrams
+        - midi-music-box
         - mbox-utility
         - med-module
         - monoid-transformer