diff --git a/COMPONENT_INDEX.md b/COMPONENT_INDEX.md
index 192fffe4..24a32634 100644
--- a/COMPONENT_INDEX.md
+++ b/COMPONENT_INDEX.md
@@ -1608,10 +1608,11 @@ None.
 
 ### Events
 
-| Event name | Type       | Detail |
-| :--------- | :--------- | :----- |
-| click      | forwarded  | --     |
-| close      | dispatched | --     |
+| Event name | Type       | Detail            |
+| :--------- | :--------- | :---------------- |
+| open       | dispatched | <code>null</code> |
+| close      | dispatched | <code>null</code> |
+| click      | forwarded  | --                |
 
 ## `HeaderActionLink`
 
diff --git a/docs/src/COMPONENT_API.json b/docs/src/COMPONENT_API.json
index 6f71b1c1..2310113f 100644
--- a/docs/src/COMPONENT_API.json
+++ b/docs/src/COMPONENT_API.json
@@ -4573,8 +4573,9 @@
         }
       ],
       "events": [
-        { "type": "forwarded", "name": "click", "element": "button" },
-        { "type": "dispatched", "name": "close" }
+        { "type": "dispatched", "name": "open", "detail": "null" },
+        { "type": "dispatched", "name": "close", "detail": "null" },
+        { "type": "forwarded", "name": "click", "element": "button" }
       ],
       "typedefs": [],
       "rest_props": { "type": "Element", "name": "button" }
diff --git a/types/UIShell/HeaderAction.svelte.d.ts b/types/UIShell/HeaderAction.svelte.d.ts
index 89c801c0..7f3ab00b 100644
--- a/types/UIShell/HeaderAction.svelte.d.ts
+++ b/types/UIShell/HeaderAction.svelte.d.ts
@@ -46,6 +46,10 @@ export interface HeaderActionProps
 
 export default class HeaderAction extends SvelteComponentTyped<
   HeaderActionProps,
-  { click: WindowEventMap["click"]; close: CustomEvent<any> },
+  {
+    open: CustomEvent<null>;
+    close: CustomEvent<null>;
+    click: WindowEventMap["click"];
+  },
   { default: {}; closeIcon: {}; icon: {}; text: {} }
 > {}