diff --git a/lib/bitauth-common.js b/lib/bitauth-common.js
index f1d0de2..195ab2e 100644
--- a/lib/bitauth-common.js
+++ b/lib/bitauth-common.js
@@ -85,7 +85,7 @@ BitAuth.getSinFromPublicKey = function(pubkey) {
 BitAuth.sign = function(data, privkey) {
   var dataBuffer;
   if (!Buffer.isBuffer(data)) {
-    dataBuffer = new Buffer(data, 'utf-8');
+    dataBuffer = new Buffer(data, 'utf8');
   } else {
     dataBuffer = data;
   }
@@ -105,7 +105,7 @@ BitAuth.sign = function(data, privkey) {
 BitAuth.verifySignature = function(data, pubkey, hexsignature, callback) {
   var dataBuffer;
   if (!Buffer.isBuffer(data)) {
-    dataBuffer = new Buffer(data, 'utf-8');
+    dataBuffer = new Buffer(data, 'utf8');
   } else {
     dataBuffer = data;
   }