diff --git a/build-constraints.yaml b/build-constraints.yaml
index 1ba32b93..2ab4ba51 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4042,7 +4042,7 @@ packages:
         - genvalidity-uuid
         - genvalidity-vector
         - mergeful
-        - mergeful-persistent
+        - mergeful-persistent < 0 # 0.1.0.0
         - mergeless
         - mergeless-persistent
         - pretty-relative-time
@@ -8180,6 +8180,7 @@ expected-test-failures:
     - krank # 0.2.3 compile fail against aeson 2
     - leveldb-haskell
     - lsp # 1.4.0.0 compile fail against aeson 2
+    - mergeless-persistent # https://github.com/commercialhaskell/stackage/issues/6566
     - mfsolve # https://github.com/commercialhaskell/stackage/issues/6379
     - multiarg # 0.30.0.10
     - mutable-containers # 0.3.4