diff --git a/acorn.js b/acorn.js
index df16c19886..3476392618 100644
--- a/acorn.js
+++ b/acorn.js
@@ -2043,7 +2043,7 @@
       // next token is a colon and the expression was a simple
       // Identifier node, we switch to interpreting it as a label.
     default:
-      if (tokType === _name && tokVal === "async") {
+      if (options.ecmaVersion >= 7 && tokType === _name && tokVal === "async") {
         var id = parseIdent();
         if (tokType === _function) {
           next();
diff --git a/package.json b/package.json
index f7e89739c3..bded093ed5 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "acorn-6to5",
   "description": "Acorn fork used by 6to5",
   "main": "acorn.js",
-  "version": "0.11.1-2",
+  "version": "0.11.1-3",
   "maintainers": [
     {
       "name": "Marijn Haverbeke",