diff --git a/src/comp/middle/trans_closure.rs b/src/comp/middle/trans_closure.rs
index 1348e35c1541..94e1cdc8ca34 100644
--- a/src/comp/middle/trans_closure.rs
+++ b/src/comp/middle/trans_closure.rs
@@ -175,6 +175,7 @@ fn store_environment(
         check trans_uniq::type_is_unique_box(bcx, box_ty);
         let r = trans_uniq::alloc_uniq(bcx, box_ty);
         add_clean_free(bcx, r.val, true);
+        temp_cleanups += [r.val];
         dummy_environment_box(bcx, r)
       }
       ty::closure_block. {