diff --git a/src/blake.js b/src/blake.js
--- a/src/blake.js
+++ b/src/blake.js
@@ -1,4 +1,5 @@
 // https://tools.ietf.org/html/rfc7693
+import {MASK,int32s2bytes,bytes2int32s} from "./util.js";
 
 const BLOCK_LEN=64;