diff --git a/build-constraints.yaml b/build-constraints.yaml
index 864c84ee..c8d0d0f4 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3914,6 +3914,9 @@ packages:
 
         # https://github.com/commercialhaskell/stackage/issues/4297
         - tomland < 1.0.0
+
+        # https://github.com/commercialhaskell/stackage/issues/4305
+        - leancheck < 0.9.0
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of