diff --git a/manual/manual.typ b/manual/manual.typ
index 4e7959d..72d8282 100644
--- a/manual/manual.typ
+++ b/manual/manual.typ
@@ -17,13 +17,18 @@
 )
 
 = Messages
+=== Server
+```json
+{"e": 0, "info": "Invalid message"}
+```
+
 == Heartbeat
 === Server
 - ```json
 {"c": "ping"}
 ```<ping>
 - ```json
-{"e": 0, "info": "Pong missed"}
+{"e": 1, "info": "Pong missed"}
 ```<pongmissed>
 
 === Device
@@ -55,13 +60,13 @@
 {"c": "auth_ok"}
 ```<auth_ok>
 - ```json
-{"e": 1, "info": "Invalid packet, wrong ID."}
+{"e": 2, "info": "Invalid packet, wrong ID."}
 ```<auth_error_id>
 - ```json
-{"e": 2, "info": "Invalid signature."} // the info doesn't matter
+{"e": 3, "info": "Invalid signature."} // the info doesn't matter
 ```<auth_error_sig>
 - ```json
-{"e": 3, "info": "Logged in at other place."} // the info doesn't matter
+{"e": 4, "info": "Logged in at other place."} // the info doesn't matter
 ```<auth_error_takeover>
 
 === Device
diff --git a/src/auth.ts b/src/auth.ts
index ecc6211..5d2ef9c 100644
--- a/src/auth.ts
+++ b/src/auth.ts
@@ -49,7 +49,7 @@ export class Authentication {
       message.d == undefined || !("id" in message.d) ||
       typeof (message.d.id) !== "string" || !(message.d.id in Device.devices)
     ) {
-      this._socket.send(buildError(1, "Invalid packet. Missing ID"));
+      this._socket.send(buildError(2, "Invalid packet. Missing ID"));
       this._socket.close();
       return;
     }
@@ -73,7 +73,7 @@ export class Authentication {
     ) return;
 
     if (this.signature !== parsed.d.signature) {
-      this._socket.send(buildError(2, "Invalid signature."));
+      this._socket.send(buildError(3, "Invalid signature."));
       this._socket.close;
       return;
     }
diff --git a/src/device.ts b/src/device.ts
index 495e274..3f10667 100644
--- a/src/device.ts
+++ b/src/device.ts
@@ -26,7 +26,7 @@ export class Device {
   }
   connect(socket: WebSocket) {
     if (this._socket !== undefined) {
-      this._socket.send(buildError(3, "Logged in at other place."))
+      this._socket.send(buildError(4, "Logged in at other place."))
       this._socket.close();
     }
     this._socket = socket;
diff --git a/src/heartbeat.ts b/src/heartbeat.ts
index e2bd58a..6ea789b 100644
--- a/src/heartbeat.ts
+++ b/src/heartbeat.ts
@@ -25,7 +25,7 @@ export class WSHeartbeat {
 
     this.socket.send(S_PING);
     this.pongTimer = setTimeout(() => {
-      this.socket.send(buildError(0, "Pong missed."));
+      this.socket.send(buildError(1, "Pong missed."));
       this.socket.close();
     }, HEARTBEAT_TIMEOUT);
   }