diff --git a/website/src/theme/Tabs/index.js b/website/src/theme/Tabs/index.js
index eaae1735a0e..eb89e07c461 100644
--- a/website/src/theme/Tabs/index.js
+++ b/website/src/theme/Tabs/index.js
@@ -1,4 +1,5 @@
 import React, { useState, cloneElement, isValidElement } from 'react';
+import ExecutionEnvironment from '@docusaurus/ExecutionEnvironment';
 import clsx from 'clsx';
 import useIsBrowser from '@docusaurus/useIsBrowser';
 import { duplicates } from '@docusaurus/theme-common';
@@ -28,7 +29,7 @@ function isTabItem(comp) {
 }
 
 function getOSName() {
-  const userAgent = navigator.userAgent;
+  const userAgent = ExecutionEnvironment.canUseDOM ? navigator.userAgent : "";
   if (userAgent.indexOf('Windows') > -1) {
     return 'Windows';
   } else if (userAgent.indexOf('Mac') > -1) {