diff --git a/build-constraints.yaml b/build-constraints.yaml
index 82018d32..b6aea3c4 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -7543,6 +7543,7 @@ expected-test-failures:
     - hsini # 0.5.1.2
     - hweblib # 0.6.3 https://github.com/aycanirican/hweblib/issues/3
     - leveldb-haskell
+    - mfsolve # https://github.com/commercialhaskell/stackage/issues/6379
     - multiarg # 0.30.0.10
     - parameterized # 0.5.0.0 https://github.com/commercialhaskell/stackage/issues/5746
     - protobuf # 0.2.1.4