diff --git a/build-constraints.yaml b/build-constraints.yaml
index 5479e9c4..26969d9f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4018,7 +4018,7 @@ packages:
         - mergeful < 0 # https://github.com/commercialhaskell/stackage/issues/6565
         - mergeful-persistent < 0 # via mergeful
         - mergeless
-        - mergeless-persistent
+        - mergeless-persistent < 0 # https://github.com/commercialhaskell/stackage/issues/6566
         - pretty-relative-time
         - safe-coloured-text
         - safe-coloured-text-gen