diff --git a/build-constraints.yaml b/build-constraints.yaml
index 3e171ee2..9bb200e5 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3865,7 +3865,7 @@ packages:
         - map-syntax < 0 # GHC 8.4 via base-4.11.0.0
         - heist < 0 # GHC 8.4 via map-syntax
         - snap < 0 # GHC 8.4 via base-4.11.0.0
-        - conferer
+        - conferer < 0.4.0.0 # https://github.com/commercialhaskell/stackage/issues/5374
         # - conferer-snap # Because snap
         - conferer-warp
         - conferer-hspec