diff --git a/src/pwd-wrap.ts b/src/pwd-wrap.ts
index ce9d9a7..43c7995 100644
--- a/src/pwd-wrap.ts
+++ b/src/pwd-wrap.ts
@@ -16,9 +16,9 @@ export default class PwdWrap {
     return await hkdf(k, Usage.wrap) as CryptoKey
   }
 
-  public static async wrap(data: CryptoKey, pwd: string, salt?: Uint8Array): Promise<PwdWrap> {
+  public static async wrap(data: CryptoKey, pwd: string): Promise<PwdWrap> {
     log.trace('wrap')
-    salt = salt ?? crypto.getRandomValues(new Uint8Array(16))
+    const salt = crypto.getRandomValues(new Uint8Array(16))
     const k = await PwdWrap.derive(pwd, salt)
     const box = await SecretWrap.wrap(data, k)
     return new PwdWrap(box, salt)