diff --git a/build-constraints.yaml b/build-constraints.yaml
index 3c1e00db..5b4da6a4 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -2964,9 +2964,6 @@ skipped-benchmarks:
     # https://github.com/athanclark/rose-trees/pull/5
     - rose-trees
 
-    # https://github.com/int-index/union/issues/4
-    - union
-
 # end of skipped-benchmarks