diff --git a/lib/6to5/traverse/global-keys.json b/lib/6to5/traverse/global-keys.json
index f616905fbd..1ff240b645 100644
--- a/lib/6to5/traverse/global-keys.json
+++ b/lib/6to5/traverse/global-keys.json
@@ -58,5 +58,7 @@
   "WeakMap",
   "WeakSet",
   "arguments",
-  "NaN"
+  "NaN",
+  "window",
+  "self"
 ]