diff --git a/lib/6to5/file.js b/lib/6to5/file.js
index 0b5906f858..24d872ffa7 100644
--- a/lib/6to5/file.js
+++ b/lib/6to5/file.js
@@ -71,6 +71,10 @@ File.normaliseOptions = function (opts) {
     opts.runtime = "to5Runtime";
   }
 
+  if (opts.playground) {
+    opts.experimental = true;
+  }
+
   transform._ensureTransformerNames("blacklist", opts.blacklist);
   transform._ensureTransformerNames("whitelist", opts.whitelist);