diff --git a/build-constraints.yaml b/build-constraints.yaml
index 20b3b13e..6b29bfdb 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3867,8 +3867,8 @@ packages:
         - snap < 0 # GHC 8.4 via base-4.11.0.0
         - conferer < 0.4.0.0 # https://github.com/commercialhaskell/stackage/issues/5374
         # - conferer-snap # Because snap
-        - conferer-warp
-        - conferer-hspec
+        - conferer-warp < 0.4.0.0 # https://github.com/commercialhaskell/stackage/issues/5374
+        - conferer-hspec < 0.4.0.0 # https://github.com/commercialhaskell/stackage/issues/5374
         - conferer-provider-json
 
     "Tim Humphries <tim+stackage@utf8.me> @thumphries":