diff --git a/build-constraints.yaml b/build-constraints.yaml
index f0c9eea5..d9114e62 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4834,6 +4834,9 @@ packages:
       # https://github.com/commercialhaskell/stackage/issues/5424
       - smallcheck < 1.2.0
 
+      # https://github.com/commercialhaskell/stackage/issues/5449
+      - unordered-containers < 0.2.11
+
     "GHC 8.10":
 
       # https://github.com/commercialhaskell/stackage/issues/5191 - compilation failures