diff --git a/stack-9.0.1.yaml b/stack-9.0.1.yaml
index 5a744f6128..c893993498 100644
--- a/stack-9.0.1.yaml
+++ b/stack-9.0.1.yaml
@@ -76,7 +76,6 @@ flags:
     pedantic: true
 
     ignore-plugins-ghc-bounds: true
-    class: false
     tactic: false # Dependencies fail
     stylishHaskell: false
     brittany: false