diff --git a/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_28.rst b/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_28.rst
index 46368ef9ea3..1699f2141e7 100644
--- a/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_28.rst
+++ b/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_28.rst
@@ -13,7 +13,7 @@ Make sure your ``appinfo/info.xml`` allows for Nextcloud 28.
.. code-block:: xml
-
+
Front-end changes
@@ -112,6 +112,20 @@ Some (minor) breaking changes were inevitable. Here's the summary:
The details of this change can also be seen in the `pull request on GitHub `__ and in the upstream documentation `dbal 3.7.x upgrade document `__.
+``symfony/event-dispatcher``
+****************************
+
+Over the last 2 major versions the ``symfony/event-dispatcher`` package first deprecated and then removed the way Nextcloud
+server dispatched old events. This means the way we wrapped away symfony's ``\Symfony\Component\EventDispatcher\EventDispatcherInterface``
+as well as using the ``\Symfony\Component\EventDispatcher\GenericEvent`` could not be kept alive in a backwards compatible way.
+
+Therefore migrating from ``\Symfony\Component\EventDispatcher\EventDispatcherInterface``
+to ``\OCP\EventDispatcher\IEventDispatcher`` (exists since Nextcloud 17) is required to be compatible with Nextcloud 28.
+All code places that dispatched a ``\Symfony\Component\EventDispatcher\GenericEvent`` have been adjusted
+and have ``\OCP\EventDispatcher\Event`` based dedicated event now that is dispatched as a typed-event so all available parameters are documented.
+
+The details of this change can also be seen in the todo items that are linked from the `pull request on GitHub `__.
+
Added APIs
^^^^^^^^^^