diff --git a/chrome/content/zotero/xpcom/schema.js b/chrome/content/zotero/xpcom/schema.js
index 175c35df2..058a520fc 100644
--- a/chrome/content/zotero/xpcom/schema.js
+++ b/chrome/content/zotero/xpcom/schema.js
@@ -1486,10 +1486,14 @@ Zotero.Schema = new function(){
 			priority: parseInt(
 				xmlnode.getElementsByTagName('priority')[0].firstChild.nodeValue
 			),
-			browserSupport: xmlnode.getAttribute('browserSupport'),
 			inRepository: true,
 		};
 		
+		var browserSupport = xmlnode.getAttribute('browserSupport');
+		if (browserSupport) {
+			metadata.browserSupport = browserSupport;
+		}
+		
 		for each(var attr in ["configOptions", "displayOptions"]) {
 			try {
 				var tags = xmlnode.getElementsByTagName(attr);