diff --git a/src/core/parser.js b/src/core/parser.js
index 887d37b40..c7e7b184b 100644
--- a/src/core/parser.js
+++ b/src/core/parser.js
@@ -24,7 +24,7 @@
 var EOF = {};
 
 function isEOF(v) {
-  return (v == EOF);
+  return (v === EOF);
 }
 
 var Parser = (function ParserClosure() {