diff --git a/build-constraints.yaml b/build-constraints.yaml
index 08a28098..72ddaa5d 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1916,7 +1916,7 @@ packages:
     "Vladislav Zavialov <vlad.z.4096@gmail.com> @int-index":
         - transformers-lift
         - ether
-        # - union # GHC 8.2.1
+        - union
 
     "Stack Builders stackage@stackbuilders.com @stackbuilders":
         - atomic-write