diff --git a/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts b/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts
index cef79c729408713cf8ef897bf946672241cea252..2a57465ebebc62fcc533314cbfc4526f3e2928ab 100644
--- a/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts
+++ b/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts
@@ -20,7 +20,7 @@ import { isEqual } from 'vs/base/common/resources';
 import { URI } from 'vs/base/common/uri';
 import { TPromise } from 'vs/base/common/winjs.base';
 import { IRemoteConsoleLog, log, parse } from 'vs/base/node/console';
-import { findFreePort } from 'vs/base/node/ports';
+import { findFreePort, randomPort } from 'vs/base/node/ports';
 import { IMessagePassingProtocol } from 'vs/base/parts/ipc/node/ipc';
 import { Protocol, generateRandomPipeName } from 'vs/base/parts/ipc/node/ipc.net';
 import { IBroadcast, IBroadcastService } from 'vs/platform/broadcast/electron-browser/broadcastService';
@@ -311,7 +311,7 @@ export class ExtensionHostProcessWorker implements IExtensionHostStarter {
 	 */
 	private _tryFindDebugPort(): Promise<{ expected: number; actual: number }> {
 		let expected: number;
-		let startPort = 9333;
+		let startPort = randomPort();
 		if (typeof this._environmentService.debugExtensionHost.port === 'number') {
 			startPort = expected = this._environmentService.debugExtensionHost.port;
 		}