diff --git a/src/vs/workbench/api/node/extHost.api.impl.ts b/src/vs/workbench/api/node/extHost.api.impl.ts
index 6d8ad575681..26a0b0646af 100644
--- a/src/vs/workbench/api/node/extHost.api.impl.ts
+++ b/src/vs/workbench/api/node/extHost.api.impl.ts
@@ -96,7 +96,7 @@ export function createApiFactory(initData: IInitData, threadService: IThreadServ
 
 		if (extension.enableProposedApi) {
 
-			if (!initData.environment.enableProposedApi) {
+			if (!initData.environment.enableProposedApi && !extension.isBuiltin) {
 				extension.enableProposedApi = false;
 				console.warn('PROPOSED API is only available when developing an extension');