diff --git a/src/vs/editor/standalone/browser/standaloneCodeEditor.ts b/src/vs/editor/standalone/browser/standaloneCodeEditor.ts
index 715c24c363b6c4349ee8bf7c22742d796b50fcbb..71cf8c51599483b70a4b3bcd262314a1d9665d3a 100644
--- a/src/vs/editor/standalone/browser/standaloneCodeEditor.ts
+++ b/src/vs/editor/standalone/browser/standaloneCodeEditor.ts
@@ -122,13 +122,13 @@ export interface IDiffEditorConstructionOptions extends IDiffEditorOptions {
 }
 
 export interface IStandaloneCodeEditor extends ICodeEditor {
-	addCommand(keybinding: number, handler: ICommandHandler, context: string): string | null;
+	addCommand(keybinding: number, handler: ICommandHandler, context?: string): string | null;
 	createContextKey<T>(key: string, defaultValue: T): IContextKey<T>;
 	addAction(descriptor: IActionDescriptor): IDisposable;
 }
 
 export interface IStandaloneDiffEditor extends IDiffEditor {
-	addCommand(keybinding: number, handler: ICommandHandler, context: string): string | null;
+	addCommand(keybinding: number, handler: ICommandHandler, context?: string): string | null;
 	createContextKey<T>(key: string, defaultValue: T): IContextKey<T>;
 	addAction(descriptor: IActionDescriptor): IDisposable;
 
@@ -182,7 +182,7 @@ export class StandaloneCodeEditor extends CodeEditorWidget implements IStandalon
 		createAriaDomNode();
 	}
 
-	public addCommand(keybinding: number, handler: ICommandHandler, context: string): string | null {
+	public addCommand(keybinding: number, handler: ICommandHandler, context?: string): string | null {
 		if (!this._standaloneKeybindingService) {
 			console.warn('Cannot add command because the editor is configured with an unrecognized KeybindingService');
 			return null;
@@ -409,7 +409,7 @@ export class StandaloneDiffEditor extends DiffEditorWidget implements IStandalon
 		return <StandaloneCodeEditor>super.getModifiedEditor();
 	}
 
-	public addCommand(keybinding: number, handler: ICommandHandler, context: string): string | null {
+	public addCommand(keybinding: number, handler: ICommandHandler, context?: string): string | null {
 		return this.getModifiedEditor().addCommand(keybinding, handler, context);
 	}
 
diff --git a/src/vs/monaco.d.ts b/src/vs/monaco.d.ts
index 937ec71136427e0311aa92fde6b4f2b21a56d0b2..35793ae2e203f9399b70d8f2ff45d3189a3ec49b 100644
--- a/src/vs/monaco.d.ts
+++ b/src/vs/monaco.d.ts
@@ -1071,13 +1071,13 @@ declare namespace monaco.editor {
 	}
 
 	export interface IStandaloneCodeEditor extends ICodeEditor {
-		addCommand(keybinding: number, handler: ICommandHandler, context: string): string | null;
+		addCommand(keybinding: number, handler: ICommandHandler, context?: string): string | null;
 		createContextKey<T>(key: string, defaultValue: T): IContextKey<T>;
 		addAction(descriptor: IActionDescriptor): IDisposable;
 	}
 
 	export interface IStandaloneDiffEditor extends IDiffEditor {
-		addCommand(keybinding: number, handler: ICommandHandler, context: string): string | null;
+		addCommand(keybinding: number, handler: ICommandHandler, context?: string): string | null;
 		createContextKey<T>(key: string, defaultValue: T): IContextKey<T>;
 		addAction(descriptor: IActionDescriptor): IDisposable;
 		getOriginalEditor(): IStandaloneCodeEditor;