diff --git a/site/content/docs/03-run-time.md b/site/content/docs/03-run-time.md
index 9a8d6a69b5..da65ac2488 100644
--- a/site/content/docs/03-run-time.md
+++ b/site/content/docs/03-run-time.md
@@ -84,6 +84,8 @@ afterUpdate(callback: () => void)
 
 Schedules a callback to run immediately after the component has been updated.
 
+> The first time the callback runs will be after the initial `onMount`
+
 ```sv
 <script>
 	import { afterUpdate } from 'svelte';