diff --git a/build-constraints.yaml b/build-constraints.yaml
index 374cd6790..6a7df8c4e 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -339,6 +339,7 @@ packages:
         - yesod-fb
         - yesod-auth-fb
         - hourglass-orphans
+        - wai-slack-middleware
 
     "haskell-openal":
         - OpenAL