diff --git a/types/undertaker/index.d.ts b/types/undertaker/index.d.ts
index cc5c772f30..8d566d1f19 100644
--- a/types/undertaker/index.d.ts
+++ b/types/undertaker/index.d.ts
@@ -12,6 +12,11 @@ declare namespace Undertaker {
         name?: string;
         displayName?: string;
         description?: string;
+        flags?: TaskFlags;
+    }
+
+    interface TaskFlags {
+        [arg: string]: string;
     }
 
     interface TaskFunction extends TaskFunctionParams {