diff --git a/.changeset/metal-spoons-scream.md b/.changeset/metal-spoons-scream.md
new file mode 100644
index 0000000000..2eb7b7140c
--- /dev/null
+++ b/.changeset/metal-spoons-scream.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: Add `closedby` property to HTMLDialogAttributes type
diff --git a/packages/svelte/elements.d.ts b/packages/svelte/elements.d.ts
index 6d256b5620..08687cafaf 100644
--- a/packages/svelte/elements.d.ts
+++ b/packages/svelte/elements.d.ts
@@ -957,6 +957,7 @@ export interface HTMLDelAttributes extends HTMLAttributes<HTMLModElement> {
 
 export interface HTMLDialogAttributes extends HTMLAttributes<HTMLDialogElement> {
 	open?: boolean | undefined | null;
+	closedby?: 'any' | 'closerequest' | 'none' | undefined | null;
 }
 
 export interface HTMLEmbedAttributes extends HTMLAttributes<HTMLEmbedElement> {