diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index b0df479dff..033bc687be 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -240,7 +240,6 @@ Services.scriptloader.loadSubScript("resource://zotero/polyfill.js");
 		this.isWin = (this.platform.substr(0, 3) == "Win");
 		this.isLinux = (this.platform.substr(0, 5) == "Linux");
 		this.oscpu = win.navigator.oscpu;
-		this.isBigSurOrLater = this.isMac && !/Mac OS X 10.([1-9]|1[0-5])/.test(win.navigator.oscpu);
 		
 		// Browser
 		Zotero.browser = "g";