diff --git a/lib/hdkey.js b/lib/hdkey.js
index c7dc805..9695488 100644
--- a/lib/hdkey.js
+++ b/lib/hdkey.js
@@ -1,6 +1,12 @@
 var assert = require('assert')
 var Buffer = require('safe-buffer').Buffer
-var crypto = require('crypto')
+var crypto = {
+  createHmac: require('create-hmac'),
+  randomBytes: require('randombytes')
+}
+var Sha256 = require('hash.js/lib/hash/sha/256')
+var RmdHash = require('hash.js/lib/hash/ripemd')
+var Ripemd160 = RmdHash.ripemd160
 var bs58check = require('bs58check')
 var secp256k1 = require('secp256k1')
 
@@ -238,8 +244,8 @@ function serialize (hdkey, version, key) {
 }
 
 function hash160 (buf) {
-  var sha = crypto.createHash('sha256').update(buf).digest()
-  return crypto.createHash('ripemd160').update(sha).digest()
+  var sha = Buffer.from(new Sha256().update(buf).digest())
+  return Buffer.from(new Ripemd160().update(sha).digest())
 }
 
 HDKey.HARDENED_OFFSET = HARDENED_OFFSET
diff --git a/package.json b/package.json
index 9466ff0..8337670 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,9 @@
   },
   "dependencies": {
     "bs58check": "^2.1.2",
+    "create-hmac": "^1.1.7",
+    "hash.js": "^1.1.7",
+    "randombytes": "^2.1.0",
     "safe-buffer": "^5.1.1",
     "secp256k1": "^4.0.0"
   },