diff --git a/src/ping.rs b/src/ping.rs
index 553411e..2a650ca 100644
--- a/src/ping.rs
+++ b/src/ping.rs
@@ -8,6 +8,7 @@ use rustls::sign::{RSASigningKey, SigningKey};
 use rustls::Certificate;
 use serde::de::{MapAccess, Visitor};
 use serde::{Deserialize, Serialize};
+use serde_repr::Deserialize_repr;
 use sodiumoxide::crypto::box_::PrecomputedKey;
 use url::Url;
 
@@ -64,7 +65,14 @@ impl<'a> From<(&'a str, &CliArgs)> for Request<'a> {
 }
 
 #[derive(Deserialize, Debug)]
-pub struct Response {
+#[serde(untagged)]
+pub enum Response {
+    Ok(OkResponse),
+    Error(ErrorResponse),
+}
+
+#[derive(Deserialize, Debug)]
+pub struct OkResponse {
     pub image_server: Url,
     pub latest_build: usize,
     pub url: Url,
@@ -76,6 +84,20 @@ pub struct Response {
     pub tls: Option<Tls>,
 }
 
+#[derive(Deserialize, Debug)]
+pub struct ErrorResponse {
+    pub error: String,
+    pub status: ErrorCode,
+}
+
+#[derive(Deserialize_repr, Debug, Copy, Clone)]
+#[repr(u16)]
+pub enum ErrorCode {
+    MalformedJson = 400,
+    InvalidSecret = 401,
+    InvalidContentType = 415,
+}
+
 pub struct Tls {
     pub created_at: String,
     pub priv_key: Arc<Box<dyn SigningKey>>,
@@ -150,7 +172,7 @@ pub async fn update_server_state(secret: &str, cli: &CliArgs, data: &mut Arc<RwL
     let resp = client.post(CONTROL_CENTER_PING_URL).json(&req).send().await;
     match resp {
         Ok(resp) => match resp.json::<Response>().await {
-            Ok(resp) => {
+            Ok(Response::Ok(resp)) => {
                 debug!("got write guard for server state");
                 let mut write_guard = data.0.write();
 
@@ -219,6 +241,12 @@ pub async fn update_server_state(secret: &str, cli: &CliArgs, data: &mut Arc<RwL
 
                 debug!("dropping write guard for server state");
             }
+            Ok(Response::Error(resp)) => {
+                error!(
+                    "Got an {} error from upstream: {}",
+                    resp.status as u16, resp.error
+                );
+            }
             Err(e) => warn!("Got malformed response: {}", e),
         },
         Err(e) => match e {
diff --git a/src/state.rs b/src/state.rs
index 66ebc35..f113d3a 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -39,6 +39,8 @@ pub enum ServerInitError {
     KeyParseError(String),
     #[error("Token key was not provided in initial request")]
     MissingTokenKey,
+    #[error("Got error response from control center")]
+    ErrorResponse,
 }
 
 impl ServerState {
@@ -56,7 +58,7 @@ impl ServerState {
 
         match resp {
             Ok(resp) => match resp.json::<Response>().await {
-                Ok(mut resp) => {
+                Ok(Response::Ok(mut resp)) => {
                     let key = resp
                         .token_key
                         .ok_or(ServerInitError::MissingTokenKey)
@@ -118,6 +120,13 @@ impl ServerState {
                         url_overridden: config.override_upstream.is_some(),
                     })
                 }
+                Ok(Response::Error(resp)) => {
+                    error!(
+                        "Got an {} error from upstream: {}",
+                        resp.status as u16, resp.error
+                    );
+                    Err(ServerInitError::ErrorResponse)
+                }
                 Err(e) => {
                     error!("Got malformed response: {}. Is MangaDex@Home down?", e);
                     Err(ServerInitError::MalformedResponse(e))