diff --git a/lib/client.js b/lib/client.js
index ee55884..14178b8 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -296,7 +296,7 @@ Client.prototype.handleConnect = function(packet, completeConnection) {
       logger.info({ username: packet.username }, "authentication error");
       client.connack({
         returnCode: 4
-      });  
+      });
       client.stream.end();
       return;
     }
diff --git a/test/abstract_server.js b/test/abstract_server.js
index dfbebad..70588ef 100644
--- a/test/abstract_server.js
+++ b/test/abstract_server.js
@@ -1026,7 +1026,25 @@ module.exports = function(moscaSettings, createConnection) {
 
       client.on('connack', function(packet) {
         expect(packet.returnCode).to.eql(5);
-        client.disconnect();
+      });
+    });
+  });
+
+  it("should support authentication (error)", function(done) {
+    instance.authenticate = function(client, username, password, callback) {
+      callback(new Error("auth error"));
+    };
+
+    buildClient(done, function(client) {
+
+      var options = buildOpts();
+      options.username = "matteo";
+      options.password = "collina";
+
+      client.connect(options);
+
+      client.on('connack', function(packet) {
+        expect(packet.returnCode).to.eql(4);
       });
     });
   });