diff --git a/lib/6to5/transformation/transformers/generators/runtime.js b/lib/6to5/transformation/transformers/generators/runtime.js
index 12330ec166..5257c4b937 100644
--- a/lib/6to5/transformation/transformers/generators/runtime.js
+++ b/lib/6to5/transformation/transformers/generators/runtime.js
@@ -8,10 +8,6 @@
 * the same directory.
 */
 
-if (typeof global.regeneratorRuntime === "object") {
-  return;
-}
-
 var iteratorSymbol = typeof Symbol === "function" && Symbol.iterator || "@@iterator";
 var runtime = global.regeneratorRuntime = exports;
 var hasOwn = Object.prototype.hasOwnProperty;