diff --git a/build-constraints.yaml b/build-constraints.yaml
index b6459d22..3b81fdf8 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -7826,6 +7826,9 @@ packages:
         # https://github.com/commercialhaskell/stackage/issues/6911
         - ghc-lib-parser < 9.6
         - ghc-lib-parser-ex < 9.6
+
+        # https://github.com/commercialhaskell/stackage/issues/6912
+        - free < 5.2
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of