diff --git a/API-Protocol.md b/API-Protocol.md
index 2a59227..8773b96 100644
--- a/API-Protocol.md
+++ b/API-Protocol.md
@@ -80,6 +80,8 @@ The client submits its APN or GCM push registration ID.
 1. `401` invalid authentication credentials.
 1. `415` badly formatted JSON.
 
+To unregister from the server, send the same request with method `DELETE`.
+
 ## Registering prekeys
 
 ```