diff --git a/gulp-typescript/gulp-typescript.d.ts b/gulp-typescript/gulp-typescript.d.ts
index d51a3122e0..690f20c30d 100644
--- a/gulp-typescript/gulp-typescript.d.ts
+++ b/gulp-typescript/gulp-typescript.d.ts
@@ -30,6 +30,7 @@ declare module "gulp-typescript" {
             jsx?: string;
             declaration?: boolean;
             emitDecoratorMetadata?: boolean;
+            experimentalDecorators?: boolean;
             experimentalAsyncFunctions?: boolean;
             moduleResolution?: string;
             noEmitHelpers?: boolean;