diff --git a/src/message.rs b/src/message.rs
index f9dfe973..bf465ee6 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -3,7 +3,7 @@ use std::collections::VecDeque;
 use std::rc::Rc;
 
 use crate::extensions::Extensions;
-use crate::http::{HeaderMap, Method, StatusCode, Uri, Version};
+use crate::http::{header, HeaderMap, Method, StatusCode, Uri, Version};
 
 /// Represents various types of connection
 #[derive(Copy, Clone, PartialEq, Debug)]
@@ -33,7 +33,15 @@ pub trait Head: Default + 'static {
     fn set_connection_type(&mut self, ctype: ConnectionType);
 
     fn upgrade(&self) -> bool {
-        self.connection_type() == ConnectionType::Upgrade
+        if let Some(hdr) = self.headers().get(header::CONNECTION) {
+            if let Ok(s) = hdr.to_str() {
+                s.to_ascii_lowercase().contains("upgrade")
+            } else {
+                false
+            }
+        } else {
+            false
+        }
     }
 
     /// Check if keep-alive is enabled
diff --git a/src/ws/mod.rs b/src/ws/mod.rs
index 3d3f5b92..88fabde9 100644
--- a/src/ws/mod.rs
+++ b/src/ws/mod.rs
@@ -132,7 +132,7 @@ pub fn verify_handshake(req: &Request) -> Result<(), HandshakeError> {
     // Check for "UPGRADE" to websocket header
     let has_hdr = if let Some(hdr) = req.headers().get(header::UPGRADE) {
         if let Ok(s) = hdr.to_str() {
-            s.to_lowercase().contains("websocket")
+            s.to_ascii_lowercase().contains("websocket")
         } else {
             false
         }