diff --git a/build-constraints.yaml b/build-constraints.yaml
index 208ddd7d..ca58ec2e 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3174,11 +3174,14 @@ packages:
         - hsyslog < 5
 
         # https://github.com/fpco/stackage/issues/2516
-        - ghc-typelits-knownnat <0.3
+        - ghc-typelits-knownnat < 0.3
 
         # https://github.com/fpco/stackage/issues/2365
         - matplotlib < 0.4.1 # still an issue with 0.4.5
 
+        # https://github.com/fpco/stackage/issues/2528
+        - concurrent-output < 1.10.0
+
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of