diff --git a/components/prism-core.js b/components/prism-core.js
index cbaa8174da..470a3b232c 100644
--- a/components/prism-core.js
+++ b/components/prism-core.js
@@ -355,7 +355,7 @@ if (!self.document) {
 		    lang = message.language,
 		    code = message.code;
 
-		self.postMessage(JSON.stringify(_.tokenize(code, _.languages[lang])));
+		self.postMessage(JSON.stringify(_.util.encode(_.tokenize(code, _.languages[lang]))));
 		self.close();
 	}, false);