diff --git a/lib/elixir/lib/module/types/descr.ex b/lib/elixir/lib/module/types/descr.ex
index fd9ee0e0118..f6231bb13c5 100644
--- a/lib/elixir/lib/module/types/descr.ex
+++ b/lib/elixir/lib/module/types/descr.ex
@@ -7030,12 +7030,12 @@ defmodule Module.Types.Descr do
   end
 
   defp opt_tuple_union(
-         bdd_leaf(tag1, elements1),
-         bdd_leaf(tag2, elements2)
+         bdd_leaf(tag1, elements1) = bdd1,
+         bdd_leaf(tag2, elements2) = bdd2
        ) do
     case opt_tuple_union_literal({tag1, elements1}, {tag2, elements2}) do
       {tag, elements} -> bdd_leaf_new(tag, elements)
-      nil -> bdd_union(bdd_leaf_new(tag1, elements1), bdd_leaf_new(tag2, elements2))
+      nil -> bdd_union(bdd1, bdd2)
     end
   end