diff --git a/lib/protocol/Auth.js b/lib/protocol/Auth.js
index 0b95ab845..e0dcdce2a 100644
--- a/lib/protocol/Auth.js
+++ b/lib/protocol/Auth.js
@@ -3,10 +3,9 @@ var Crypto = require('crypto');
 var Auth   = exports;
 
 var sha1;
-if (Number(process.version.match(/^v\d+\.(\d+)/)[1]) >= 10){
+if (typeof Crypto.createHash.write == 'function') {
   sha1 = function(msg) {
     var hash = Crypto.createHash('sha1');
-    hash.setEncoding('binary');
     hash.write(msg);
     hash.end();
     return hash.read();