diff --git a/lib/index.js b/lib/index.js
index c62a052..d4bfda4 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -193,7 +193,7 @@ function OutBatch() {
 
 OutBatch.prototype.append = function (buf, flags, cb) {
   if (typeof buf === 'string') {
-    buf = new Buffer(String(buf), 'utf8');
+    buf = new Buffer(buf, 'utf8');
   } else if (!Buffer.isBuffer(buf)) {
     throw new TypeError('ZeroMQ only supports Buffers or Strings as messages');
   }