diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index 6848cfde3..b4676b4d2 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -124,7 +124,8 @@ var Zotero = new function(){
 				getService(Components.interfaces.nsIXULAppInfo)
 		this.isFx2 = appInfo.platformVersion.indexOf('1.8') === 0; // TODO: remove
 		this.isFx3 = appInfo.platformVersion.indexOf('1.9') === 0;
-		this.isFx30 = appInfo.platformVersion.indexOf('1.9.0') === 0;
+		this.isFx30 = appInfo.platformVersion == '1.9'
+						|| appInfo.platformVersion.indexOf('1.9.0') === 0;
 		this.isFx31 = appInfo.platformVersion.indexOf('1.9.1') === 0;
 		
 		// OS platform