diff --git a/build-constraints.yaml b/build-constraints.yaml
index 19498161..2d2e3b6c 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3680,6 +3680,9 @@ packages:
         # https://github.com/commercialhaskell/stackage/issues/3931
         - proto-lens-protobuf-types < 0.3.0.2
 
+        # https://github.com/commercialhaskell/stackage/issues/3944
+        - deferred-folds < 0.9
+
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of