# The test "our browser is outdated" can be fooled

**URL:** https://meta.discourse.org/t/the-test-our-browser-is-outdated-can-be-fooled/379951
**Category:** Bug
**Created:** [August 22, 2025, 7:01pm UTC](https://meta.discourse.org/t/the-test-our-browser-is-outdated-can-be-fooled/379951 "2025-08-22T19:01:29Z")
**Posts on this page:** 1
**Showing post:** 1

<div class="post-metadata">

### Author: ![Aneta\_Zelek](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/aneta_zelek/32/160783_2.png) [@Aneta\_Zelek](https://meta.discourse.org/u/Aneta_Zelek)
#### Post date: [August 22, 2025, 7:01pm UTC](https://meta.discourse.org/t/the-test-our-browser-is-outdated-can-be-fooled/379951/1 "2025-08-22T19:01:29Z")

</div>

I noticed that the latest check on `meta.discourse.org` or `discover.discourse.com` to avoid viewing pages in modern mode on e.g. Firefox 115.27.0 can be circumvented by uBlock Origin, AdGuard, or even AdBlock/Adblock Plus:

```plaintext
! One of the four is sufficient:
meta.discourse.org##+js(aopw, unsupportedBrowser)
! Less stable:
meta.discourse.org##+js(set, unsupportedBrowser, undefined)
meta.discourse.org##+js(set, unsupportedBrowser, false)
meta.discourse.org##+js(set, unsupportedBrowser, '')
! Once every few dozen views, race mode may occur when using the set-constant version, causing the content blocker to fail when we rely on it, and the correct preview will be enabled in simplified HTML.

```

- `aopw` = `abort-on-property-write`\[1\]
- `set` = `set-constant`\[2\]_(`override-property-read` for AdBlock and ABP)_

Perhaps it should use a more secure method? One now visible disadvantage is that footnotes inserted into replies or introductory posts definitely do not work with this trick (Perhaps it is using CSS (other than the known issue with Relative Colour Syntax) or JS that is too new).

* * *

1. [Resources Library · gorhill/uBlock Wiki · GitHub **#abort-on-property-writejs-**](https://github.com/gorhill/ublock/wiki/Resources-Library#abort-on-property-writejs-) 

2. [Resources Library · gorhill/uBlock Wiki · GitHub **#set-constantjs-**](https://github.com/gorhill/ublock/wiki/Resources-Library#set-constantjs-)

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