diff --git a/lib/6to5/transformation/transformers/_alias-functions.js b/lib/6to5/transformation/transformers/_alias-functions.js
index 2230a44e9a..5cf9003c84 100644
--- a/lib/6to5/transformation/transformers/_alias-functions.js
+++ b/lib/6to5/transformation/transformers/_alias-functions.js
@@ -67,7 +67,7 @@ var go = function (getBody, node, file, scope) {
   }
 
   if (thisId) {
-    pushDeclaration(thisId, t.identifier("this"));
+    pushDeclaration(thisId, t.thisExpression());
   }
 };