--- a/toolkit/components/thumbnails/test/browser_thumbnails_bg_no_cookies_stored.js
+++ b/toolkit/components/thumbnails/test/browser_thumbnails_bg_no_cookies_stored.js
@@ -1,16 +1,16 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // check that if a page captured in the background attempts to set a cookie,
 // that cookie is not saved for subsequent requests.
 function* runTests() {
   yield SpecialPowers.pushPrefEnv({
-    set: [["privacy.about_newtab_segragation.enabled", true]]
+    set: [["privacy.about_newtab_segregation.enabled", true]]
   });
 
   let url = bgTestPageURL({
     setRedCookie: true,
     iframe: bgTestPageURL({ setRedCookie: true}),
     xhr: bgTestPageURL({ setRedCookie: true})
   });
   ok(!thumbnailExists(url), "Thumbnail file should not exist before capture.");