diff --git a/build-constraints.yaml b/build-constraints.yaml
index 7264ca39..1f463230 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1318,7 +1318,7 @@ packages:
         - prompt
         - tagged-binary
         - typelits-witnesses
-        # BLOCKED comonad 5 - uncertain
+        - uncertain
 
     "Ian Duncan <ian@iankduncan.com> @iand675":
         - feature-flags