diff --git a/index.js b/index.js
index cc7a920..e9c003e 100644
--- a/index.js
+++ b/index.js
@@ -36,7 +36,7 @@ mixpanel_exporter.prototype.alphabetical_sort = function(obj) {
     }, {})
 }
 mixpanel_exporter.prototype.hash = function(string) {
-    return crypto.createHash('md5').update(string).digest('hex')
+    return crypto.createHash('md5').update(new Buffer(string).toString('binary')).digest('hex')
 }
 mixpanel_exporter.prototype.get_signature = function(obj) {
     return this.hash(_.reduce(obj, function(sig, val, key) {
diff --git a/test/format.test.js b/test/format.test.js
index 0b02f53..9c13938 100644
--- a/test/format.test.js
+++ b/test/format.test.js
@@ -82,7 +82,10 @@ describe('Methods', function() {
     })
     describe('Hash', function() {
         it('should md5 a string', function() {
-            var md5 = require('crypto').createHash('md5').update('hash_me').digest('hex').should.equal(obj.hash('hash_me'))
+            var md5 = require('crypto').createHash('md5').update(new Buffer('hash_me').toString('binary')).digest('hex').should.equal(obj.hash('hash_me'))
+        })
+        it('should md5 a string with utf-8 characters', function() {
+            var md5 = require('crypto').createHash('md5').update(new Buffer('®ÀÆæ中さたな').toString('binary')).digest('hex').should.equal(obj.hash('®ÀÆæ中さたな'))
         })
     })
     describe('Signature', function() {