diff --git a/lib/6to5/transformation/helpers/build-conditional-assignment-operator-transformer.js b/lib/6to5/transformation/helpers/build-conditional-assignment-operator-transformer.js
index 154588db85..adb097052f 100644
--- a/lib/6to5/transformation/helpers/build-conditional-assignment-operator-transformer.js
+++ b/lib/6to5/transformation/helpers/build-conditional-assignment-operator-transformer.js
@@ -35,6 +35,7 @@ module.exports = function (exports, opts) {
       buildAssignment(exploded.ref, node.right)
     ));
 
+    // todo: duplicate expression node
     nodes.push(exploded.ref);
 
     return t.toSequenceExpression(nodes, scope);