# Tip: Compatibility mode deprecation

**URL:** <https://cylc.discourse.group/t/tip-compatibility-mode-deprecation/1232>\
**Category:** Cylc Announce\
**Created:** [August 14, 2025, 12:12pm UTC](https://cylc.discourse.group/t/tip-compatibility-mode-deprecation/1232 "2025-08-14T12:12:00Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![oliver.sanders](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/oliver.sanders/32/110_2.png) [@oliver.sanders](https://cylc.discourse.group/u/oliver.sanders)\
**Post date:** [August 14, 2025, 12:12pm UTC](https://cylc.discourse.group/t/tip-compatibility-mode-deprecation/1232/1 "2025-08-14T12:12:00Z")

</div>

As of Cylc 8.5.0, the [Cylc 7 compatibility mode](https://cylc.github.io/cylc-doc/stable/html/7-to-8/major-changes/compatibility-mode.html#cylc-7-compat-mode) has been deprecated, it will be removed in Cylc 8.7.0 which is expected to be released some time in the first half of 2026.

This means that any workflows that are still using `suite.rc` files will need to be upgraded to `flow.cylc` before they are able to run with 8.7.0.