diff --git a/src/server.js b/src/server.js
index 71174f3..9e89bb5 100644
--- a/src/server.js
+++ b/src/server.js
@@ -9,6 +9,7 @@ const ERR_UNKNOWNCOMMAND = '421'
 const ERR_ERRONEUSNICKNAME = '432'
 const ERR_NICKNAMEINUSE = '433'
 const ERR_NEEDMOREPARAMS = '461'
+const ERR_NONICKNAMEGIVEN = '431'
 
 let server = {}
 let registeredUserlist = require("../src/userlist.js")
@@ -29,17 +30,18 @@ server.create = function create() {
                     if (tokenized[1]) {
                         let nickname = tokenized[1]
                         // nick collision test
+                        console.log(Object.keys(registeredUserlist));
                         if (!Object.keys(registeredUserlist).includes(nickname)) {
                             user.setNickname(nickname)
                             registeredUserlist[nickname] = user
-                            socket.write(RPL_WELCOME, " nick " + nickname + " succesfully added.")
+                            socket.write(RPL_WELCOME, " nick " + nickname + " succesfully added.\r\n")
                         } else {
-                            socket.write(ERR_NICKNAMEINUSE, " nickname in use")
+                            socket.write(ERR_NICKNAMEINUSE, " nickname in use\r\n")
                         }
 
 
                     } else {
-                        socket.write("ERROR: NO NICKNAME PROVIDED")
+                        socket.write(ERR_NONICKNAMEGIVEN, " :No nickname given\r\n")
                     }
 
                     break;
diff --git a/test/server.js b/test/server.js
index cd894f8..cb022be 100644
--- a/test/server.js
+++ b/test/server.js
@@ -40,5 +40,20 @@ describe('IRC server', function() {
             server.emit("connection", mockedSock)
             mockedSock.emit('data', Buffer.from("NICK some_nick\r\n", "ascii"))
         })
+
+        it("should send 431 on NICK command with no parameter -> NICK", function (done) {
+            const server = IRCServer.create()
+            let mockedSock = new EventEmitter()
+            mockedSock.write = function (data) {
+                assert.equal(data.toString("ascii"), "431")
+                done()
+            }
+            mockedSock.destroy = function () {
+                done("Destroyed socket without answering")
+            }
+
+            server.emit("connection", mockedSock)
+            mockedSock.emit('data', Buffer.from("NICK\r\n", "ascii"))
+        })
     })
 })