diff --git a/src/main.rs b/src/main.rs
index 2133644..32bfe72 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -36,7 +36,7 @@ async fn root() -> &'static str {
     "KOreader sync server"
 }
 
-async fn create_user(Json(payload): Json<User>) -> StatusCode {
+async fn create_user(Json(payload): Json<User>) -> (StatusCode, String) {
     let client = redis::Client::open("redis://127.0.0.1/").unwrap();
     let mut con = client.get_connection().unwrap();
 
@@ -50,10 +50,13 @@ async fn create_user(Json(payload): Json<User>) -> StatusCode {
     if does_exist == false {
         let _: () = con.set(&user_key, password).unwrap();
     } else {
-        return StatusCode::PAYMENT_REQUIRED;
+        return (
+            StatusCode::PAYMENT_REQUIRED,
+            "Username is already registered.".to_owned(),
+        );
     }
 
-    StatusCode::CREATED
+    (StatusCode::CREATED, format!("username = {username}"))
 }
 
 async fn auth_user(headers: HeaderMap) -> StatusCode {