diff --git a/docs/capabilities.md b/docs/capabilities.md
index 71adb3223a13..83ad659aedd4 100644
--- a/docs/capabilities.md
+++ b/docs/capabilities.md
@@ -154,3 +154,6 @@
 * `ban-v1` - Whether the API to ban attendees is available
 * `mention-permissions` - Whether non-moderators are allowed to mention `@all`
 * `federation-v2` - Whether federated session ids are used and calls are possible with federation
+
+## 21
+* `edit-messages-note-to-self` - Messages in note-to-self conversations can be edited indefinitely
\ No newline at end of file
diff --git a/lib/Capabilities.php b/lib/Capabilities.php
index 66952a5da4ab..86c9577c378b 100644
--- a/lib/Capabilities.php
+++ b/lib/Capabilities.php
@@ -102,6 +102,7 @@ class Capabilities implements IPublicCapability {
 		'ban-v1',
 		'chat-reference-id',
 		'mention-permissions',
+		'edit-messages-note-to-self',
 	];
 
 	public const LOCAL_FEATURES = [