diff --git a/build-constraints.yaml b/build-constraints.yaml
index af2033ae..d3e2cd49 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -2101,10 +2101,10 @@ packages:
 
     "Will Coster <willcoster@gmail.com> @fimad":
         - prometheus-client
-        - prometheus-metrics-ghc < 0 # Build failure: https://github.com/fimad/prometheus-haskell/issues/39
+        - prometheus-metrics-ghc
         - scalpel
         - scalpel-core
-        - wai-middleware-prometheus < 0 # GHC 8.4 via prometheus-client
+        - wai-middleware-prometheus
 
     "William Casarin <bill@casarin.me> @jb55":
         - bson-lens < 0 # via bson
@@ -5143,6 +5143,7 @@ packages:
       # https://github.com/commercialhaskell/stackage/issues/5747
       - http-client < 0.7
       - http-client-openssl < 0.3.3
+      - req < 3.9.1
 
       # https://github.com/commercialhaskell/stackage/issues/5836
       - clock < 0.8.2