diff --git a/vscode.proposed.d.ts b/vscode.proposed.d.ts
index b803dce0f8..4c4b4f9be6 100644
--- a/vscode.proposed.d.ts
+++ b/vscode.proposed.d.ts
@@ -233,6 +233,12 @@ declare module 'vscode' {
 		 * The document's current run state
 		 */
 		runState?: NotebookRunState;
+
+		/**
+		 * Whether the document is trusted, default to true
+		 * When false, insecure outputs like HTML, JavaScript, SVG will not be rendered.
+		 */
+		trusted?: boolean;
 	}
 
 	export interface NotebookDocumentContentOptions {