diff --git a/lib/scrypt.js b/lib/scrypt.js
index feca2cc..440dc52 100644
--- a/lib/scrypt.js
+++ b/lib/scrypt.js
@@ -1,6 +1,6 @@
 var pbkdf2 = require('pbkdf2-sha256')
 
-var MAX_VALUE = 2147483647
+var MAX_VALUE = 0x7fffffff
 
 // N = Cpu cost, r = Memory cost, p = parallelization cost
 function scrypt(key, salt, N, r, p, dkLen) {