Created attachment 239988 [details] Repro page Steps to reproduce the problem: 1. Open toggleRTL.html (attached) What is the expected behavior? The final direction should be LTR. The script should output: Switched to '' getComputedStyle(document.documentElement).direction is ltr What went wrong? The final direction is actually RTL. The script outputs: Switched to '' getComputedStyle(document.documentElement).direction is rtl This works in IE 11 and Firefox 32