diff --git a/build-constraints.yaml b/build-constraints.yaml
index c7961b0b..5530a5b0 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -49,6 +49,7 @@ packages:
         - lzma-conduit
         - mutable-containers
         - hpc-coveralls
+        - monad-unlift
 
     "FP Complete michael@fpcomplete.com @snoyberg":
         - alex