diff --git a/core/lib/src/response/response.rs b/core/lib/src/response/response.rs
index d01bc004..2e1fdfa8 100644
--- a/core/lib/src/response/response.rs
+++ b/core/lib/src/response/response.rs
@@ -794,11 +794,29 @@ impl<'r> Response<'r> {
         &self.body
     }
 
+    /// Returns `Ok(Some(_))` if `self` contains a suitable handler for any of
+    /// the comma-separated protocols any of the strings in `I`. Returns
+    /// `Ok(None)` if `self` doesn't support any kind of upgrade. Returns
+    /// `Err(_)` if `protocols` is non-empty but no match was found in `self`.
     pub(crate) fn take_upgrade<I: Iterator<Item = &'r str>>(
         &mut self,
-        mut protocols: I
-    ) -> Option<(Uncased<'r>, Box<dyn IoHandler + 'r>)> {
-        protocols.find_map(|p| self.upgrade.remove_entry(p.as_uncased()))
+        protocols: I
+    ) -> Result<Option<(Uncased<'r>, Box<dyn IoHandler + 'r>)>, ()> {
+        if self.upgrade.is_empty() {
+            return Ok(None);
+        }
+
+        let mut protocols = protocols.peekable();
+        let have_protocols = protocols.peek().is_some();
+        let found = protocols
+            .flat_map(|v| v.split(',').map(str::trim))
+            .find_map(|p| self.upgrade.remove_entry(p.as_uncased()));
+
+        match found {
+            Some(handler) => Ok(Some(handler)),
+            None if have_protocols => Err(()),
+            None => Ok(None)
+        }
     }
 
     /// Returns the [`IoHandler`] for the protocol `proto`.
diff --git a/core/lib/src/server.rs b/core/lib/src/server.rs
index 213a3214..6b315ed0 100644
--- a/core/lib/src/server.rs
+++ b/core/lib/src/server.rs
@@ -86,9 +86,14 @@ async fn hyper_service_fn(
                 let token = rocket.preprocess_request(&mut req, &mut data).await;
                 let mut response = rocket.dispatch(token, &req, data).await;
                 let upgrade = response.take_upgrade(req.headers().get("upgrade"));
-                if let Some((proto, handler)) = upgrade {
+                if let Ok(Some((proto, handler))) = upgrade {
                     rocket.handle_upgrade(response, proto, handler, pending_upgrade, tx).await;
                 } else {
+                    if upgrade.is_err() {
+                        warn_!("Request wants upgrade but no I/O handler matched.");
+                        info_!("Request is not being upgraded.");
+                    }
+
                     rocket.send_response(response, tx).await;
                 }
             },
diff --git a/examples/upgrade/src/ws.rs b/examples/upgrade/src/ws.rs
index 7122a801..ace8c5fa 100644
--- a/examples/upgrade/src/ws.rs
+++ b/examples/upgrade/src/ws.rs
@@ -25,8 +25,12 @@ impl<'r> FromRequest<'r> for WebSocket {
         use rocket::http::uncased::eq;
 
         let headers = req.headers();
-        let is_upgrade = headers.get_one("Connection").map_or(false, |c| eq(c, "upgrade"));
-        let is_ws = headers.get("Upgrade").any(|p| eq(p, "websocket"));
+        let is_upgrade = headers.get("Connection")
+            .any(|h| h.split(',').any(|v| eq(v.trim(), "upgrade")));
+
+        let is_ws = headers.get("Upgrade")
+            .any(|h| h.split(',').any(|v| eq(v.trim(), "websocket")));
+
         let is_ws_13 = headers.get_one("Sec-WebSocket-Version").map_or(false, |v| v == "13");
         let key = headers.get_one("Sec-WebSocket-Key").map(|k| derive_accept_key(k.as_bytes()));
         match key {