# Uppercase letters in username break reachable mention check in composer

**URL:** https://meta.discourse.org/t/uppercase-letters-in-username-break-reachable-mention-check-in-composer/401292
**Category:** Bug
**Tags:** mentions
**Created:** [22 april 2026 om 19:47 UTC](https://meta.discourse.org/t/uppercase-letters-in-username-break-reachable-mention-check-in-composer/401292 "2026-04-22T19:47:26Z")
**Posts on this page:** 1
**Showing post:** 4

<div class="post-metadata">

### Author: ![zogstrip](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/zogstrip/32/512781_2.png) [@zogstrip](https://meta.discourse.org/u/zogstrip)
#### Post date: [23 april 2026 om 08:34 UTC](https://meta.discourse.org/t/uppercase-letters-in-username-break-reachable-mention-check-in-composer/401292/4 "2026-04-23T08:34:26Z")

</div>

The correct fix is

[https://github.com/discourse/discourse/pull/37177](https://github.com/discourse/discourse/pull/37177)

but it’s too big a change than I’m confortable merging at this point 😬

Instead, I’m going to fix each “endpoints” one by one to make it simpler to review and less risky.

Here’s first step

[https://github.com/discourse/discourse/pull/39482](https://github.com/discourse/discourse/pull/39482)

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