diff --git a/src/mercury/mod.rs b/src/mercury/mod.rs
index 58df0cd..3651740 100644
--- a/src/mercury/mod.rs
+++ b/src/mercury/mod.rs
@@ -101,9 +101,10 @@ impl MercuryManager {
     pub fn subscribe<T: Into<String>>(&self, uri: T)
         -> BoxFuture<mpsc::UnboundedReceiver<MercuryResponse>, MercuryError>
     {
+        let uri = uri.into();
         let request = self.request(MercuryRequest {
             method: MercuryMethod::SUB,
-            uri: uri.into(),
+            uri: uri.clone(),
             content_type: None,
             payload: Vec::new(),
         });
@@ -116,8 +117,11 @@ impl MercuryManager {
                 for sub in response.payload {
                     let mut sub : protocol::pubsub::Subscription
                         = protobuf::parse_from_bytes(&sub).unwrap();
-                    let uri = sub.take_uri();
-                    inner.subscriptions.insert(uri, tx.clone());
+                    let sub_uri = sub.take_uri();
+
+                    debug!("subscribed {} ({})", uri, sub_uri);
+
+                    inner.subscriptions.insert(sub_uri, tx.clone());
                 }
             });
 
@@ -181,21 +185,29 @@ impl MercuryManager {
 
         let response = MercuryResponse {
             uri: header.get_uri().to_owned(),
+            status_code: header.get_status_code(),
             payload: pending.parts,
         };
 
-        if cmd == 0xb5 {
-            self.lock(|inner| {
-                use std::collections::hash_map::Entry;
-                if let Entry::Occupied(entry) = inner.subscriptions.entry(response.uri.clone()) {
-                    // TODO: send unsub message
-                    if entry.get().send(response).is_err() {
-                        entry.remove();
+        if response.status_code >= 400 {
+            warn!("error {} for uri {}", response.status_code, &response.uri);
+            if let Some(cb) = pending.callback {
+                cb.complete(Err(MercuryError));
+            }
+        } else {
+            if cmd == 0xb5 {
+                self.lock(|inner| {
+                    use std::collections::hash_map::Entry;
+                    if let Entry::Occupied(entry) = inner.subscriptions.entry(response.uri.clone()) {
+                        // TODO: send unsub message
+                        if entry.get().send(response).is_err() {
+                            entry.remove();
+                        }
                     }
-                }
-            })
-        } else if let Some(cb) = pending.callback {
-            cb.complete(Ok(response));
+                })
+            } else if let Some(cb) = pending.callback {
+                cb.complete(Ok(response));
+            }
         }
     }
 }
diff --git a/src/mercury/types.rs b/src/mercury/types.rs
index aa33af2..2268330 100644
--- a/src/mercury/types.rs
+++ b/src/mercury/types.rs
@@ -23,6 +23,7 @@ pub struct MercuryRequest {
 #[derive(Debug)]
 pub struct MercuryResponse {
     pub uri: String,
+    pub status_code: i32,
     pub payload: Vec<Vec<u8>>,
 }