diff --git a/types/uid-safe/index.d.ts b/types/uid-safe/index.d.ts
index ee7b13491f..20a85ae899 100644
--- a/types/uid-safe/index.d.ts
+++ b/types/uid-safe/index.d.ts
@@ -8,7 +8,7 @@ declare namespace UID {
     export interface Generate {
 
         (byteLength: number, callback: (err: any, str: string) => any): void;
-        (byteLength: number): Promise<any>;
+        (byteLength: number): Promise<string>;
 
         sync(byteLength: number): string;
     }