diff --git a/src/vs/platform/commands/common/commandService.ts b/src/vs/platform/commands/common/commandService.ts
index c3844d25288bdc84dc6a329317c3bad30ee35187..2821e462d41746419162693eff7675a7b50f8f30 100644
--- a/src/vs/platform/commands/common/commandService.ts
+++ b/src/vs/platform/commands/common/commandService.ts
@@ -37,4 +37,14 @@ export class CommandService implements ICommandService {
 			}
 		});
 	}
+
+	isKnownCommand(commandId: string): boolean {
+		const command = CommandsRegistry.getCommand(commandId);
+
+		if (!command) {
+			return false;
+		}
+
+		return true;
+	}
 }
diff --git a/src/vs/platform/commands/common/commands.ts b/src/vs/platform/commands/common/commands.ts
index 0dbb3c3b3133b72077eea3e8fd99e35510413ff9..1c4542c95953a475fdc55cbdeddc8b3063d8b598 100644
--- a/src/vs/platform/commands/common/commands.ts
+++ b/src/vs/platform/commands/common/commands.ts
@@ -14,6 +14,7 @@ export interface ICommandService {
 	serviceId: ServiceIdentifier<any>;
 	executeCommand<T>(commandId: string, ...args: any[]): TPromise<T>;
 	executeCommand(commandId: string, ...args: any[]): TPromise<any>;
+	isKnownCommand(commandId: string): boolean;
 }
 
 export interface ICommandsMap {
@@ -99,5 +100,8 @@ export const NullCommandService: ICommandService = {
 	serviceId: undefined,
 	executeCommand() {
 		return TPromise.as(undefined);
+	},
+	isKnownCommand() {
+		return false;
 	}
 };
\ No newline at end of file
diff --git a/src/vs/workbench/electron-browser/integration.ts b/src/vs/workbench/electron-browser/integration.ts
index faaa4c2d47e675169d9b6f75dd0198f28bb386c5..8576845fb54372dd2928962217dd32ac860f9ee0 100644
--- a/src/vs/workbench/electron-browser/integration.ts
+++ b/src/vs/workbench/electron-browser/integration.ts
@@ -172,6 +172,9 @@ export class ElectronIntegration {
 	private resolveKeybindings(actionIds: string[]): TPromise<{ id: string; binding: number; }[]> {
 		return this.partService.joinCreation().then(() => {
 			return arrays.coalesce(actionIds.map((id) => {
+				if (!this.commandService.isKnownCommand(id)) {
+					console.warn('Menu uses unknown command: ' + id);
+				}
 				let bindings = this.keybindingService.lookupKeybindings(id);
 
 				// return the first binding that can be represented by electron
diff --git a/src/vs/workbench/test/node/api/extHostApiCommands.test.ts b/src/vs/workbench/test/node/api/extHostApiCommands.test.ts
index ccf5af8b225b7c4e5c90007c3b4c98c6151da234..dc5b8b05625b464a92bc19cc570f0756b03dbaf0 100644
--- a/src/vs/workbench/test/node/api/extHostApiCommands.test.ts
+++ b/src/vs/workbench/test/node/api/extHostApiCommands.test.ts
@@ -64,6 +64,9 @@ suite('ExtHostLanguageFeatureCommands', function() {
 			executeCommand(id, args): any {
 				let {handler} = CommandsRegistry.getCommands()[id];
 				return TPromise.as(instantiationService.invokeFunction(handler, args));
+			},
+			isKnownCommand(id) {
+				return true;
 			}
 		});
 		services.set(IMarkerService, new MarkerService());