diff --git a/src/vs/platform/extensionManagement/node/extensionManagementService.ts b/src/vs/platform/extensionManagement/node/extensionManagementService.ts
index 491fcf206cdf241c964fba07c690366c4abfeb9f..7bf650b20bbc948f382d05cba3ee1bcfb5911beb 100644
--- a/src/vs/platform/extensionManagement/node/extensionManagementService.ts
+++ b/src/vs/platform/extensionManagement/node/extensionManagementService.ts
@@ -573,6 +573,7 @@ export class ExtensionManagementService implements IExtensionManagementService {
 
 	removeDeprecatedExtensions(): TPromise<any> {
 		return TPromise.join([
+			// Remove obsolte extensions first to avoid removing installed older extension. See #38609.
 			this.removeObsoleteExtensions(),
 			this.removeOutdatedExtensions()
 		]);