diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index b8c43215dddf29bcc5f128f4a9faa80f8e68cab6..891ffe7d8d5c7c765902dcdaa5c8894405045078 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -7333,7 +7333,8 @@ declare module 'vscode' {
 		export function registerTextDocumentContentProvider(scheme: string, provider: TextDocumentContentProvider): Disposable;
 
 		/**
-		 * An event that is emitted when a [text document](#TextDocument) is opened.
+		 * An event that is emitted when a [text document](#TextDocument) is opened or when the language id
+		 * of a text document [has been changed](#languages.setTextDocumentLanguage).
 		 *
 		 * To add an event listener when a visible text document is opened, use the [TextEditor](#TextEditor) events in the
 		 * [window](#window) namespace. Note that:
@@ -7346,7 +7347,8 @@ declare module 'vscode' {
 		export const onDidOpenTextDocument: Event<TextDocument>;
 
 		/**
-		 * An event that is emitted when a [text document](#TextDocument) is disposed.
+		 * An event that is emitted when a [text document](#TextDocument) is disposed or when the language id
+		 * of a text document [has been changed](#languages.setTextDocumentLanguage).
 		 *
 		 * To add an event listener when a visible text document is closed, use the [TextEditor](#TextEditor) events in the
 		 * [window](#window) namespace. Note that this event is not emitted when a [TextEditor](#TextEditor) is closed