diff --git a/src/client.js b/src/client.js
index b1bae1f..7a73438 100644
--- a/src/client.js
+++ b/src/client.js
@@ -114,7 +114,7 @@ class Client extends EventEmitter
 
   end(reason) {
     this._endReason = reason;
-    this.socket.end();
+    if(this.socket) this.socket.end();
   }
 
   setEncryption(sharedSecret) {
diff --git a/src/createServer.js b/src/createServer.js
index 7e81f0d..b0a7487 100644
--- a/src/createServer.js
+++ b/src/createServer.js
@@ -146,6 +146,10 @@ function createServer(options) {
       } else if(packet.nextState == 2) {
         client.state = states.LOGIN;
       }
+      if(client.protocolVersion!=version.version)
+      {
+        client.end("Wrong protocol version, expected : "+version.version+" and you are using : "+client.protocolVersion);
+      }
     }
 
     function onEncryptionKeyResponse(packet) {