diff --git a/vscode.proposed.d.ts b/vscode.proposed.d.ts
index fde3199ea4..71edb59e6d 100644
--- a/vscode.proposed.d.ts
+++ b/vscode.proposed.d.ts
@@ -567,6 +567,7 @@ declare module 'vscode' {
 
 		export const onDidOpenNotebookDocument: Event<NotebookDocument>;
 		export const onDidCloseNotebookDocument: Event<NotebookDocument>;
+		export const onDidSaveNotebookDocument: Event<NotebookDocument>;
 
 		/**
 		 * All currently known notebook documents.