diff --git a/acorn_loose.js b/acorn_loose.js
index 97a4dd036e..6f7023c47e 100644
--- a/acorn_loose.js
+++ b/acorn_loose.js
@@ -44,6 +44,7 @@
     fetchToken = acorn.tokenize(inpt, opts);
     context = [];
     nextLineStart = 0;
+    ahead.length = 0;
     next();
     return parseTopLevel();
   };