diff --git a/src/Ed25519Keypair.js b/src/Ed25519Keypair.js
index 8c8b9b0..b94d668 100644
--- a/src/Ed25519Keypair.js
+++ b/src/Ed25519Keypair.js
@@ -15,7 +15,7 @@ import nacl from 'tweetnacl'
  */
 export default function Ed25519Keypair(seed) {
     const keyPair = seed ? nacl.sign.keyPair.fromSeed(seed) : nacl.sign.keyPair()
-    this.publicKey = base58.encode(keyPair.publicKey)
+    this.publicKey = base58.encode(new Buffer(keyPair.publicKey))
     // tweetnacl's generated secret key is the secret key + public key (resulting in a 64-byte buffer)
-    this.privateKey = base58.encode(keyPair.secretKey.slice(0, 32))
+    this.privateKey = base58.encode(new Buffer(keyPair.secretKey.slice(0, 32)))
 }