diff --git a/build-constraints.yaml b/build-constraints.yaml
index 48be22df..c215ae2f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -7270,6 +7270,7 @@ expected-test-failures:
     - hpack-dhall # https://github.com/BlockScope/hpack-dhall/issues/25
     - lucid # https://github.com/chrisdone/lucid/issues/109
     - lz4-frame-conduit # https://github.com/nh2/lz4-frame-conduit/issues/3
+    - mighty-metropolis # https://github.com/jtobin/mighty-metropolis/issues/6
     - mmark # https://github.com/mmark-md/mmark/issues/80
     - mmark-ext # https://github.com/mmark-md/mmark/issues/80
     - nettle # https://github.com/stbuehler/haskell-nettle/issues/10