diff --git a/build-constraints.yaml b/build-constraints.yaml
index c87506c4..89433373 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3754,6 +3754,7 @@ expected-test-failures:
     - commutative # https://github.com/athanclark/commutative/issues/4
     - dbus # 0.10.12 No issue tracker, e-mail sent to maintainer
     - flat # https://github.com/Quid2/flat/issues/1
+    - foundation # https://github.com/haskell-foundation/foundation/issues/394
     - haddock
     - heap # https://github.com/pruvisto/heap/issues/4
     - hledger-iadd # https://github.com/hpdeifel/hledger-iadd/issues/26