diff --git a/rpxy-lib/src/message_handler/handler_main.rs b/rpxy-lib/src/message_handler/handler_main.rs
index 4b324df..23133a2 100644
--- a/rpxy-lib/src/message_handler/handler_main.rs
+++ b/rpxy-lib/src/message_handler/handler_main.rs
@@ -200,7 +200,7 @@ where
     // Handle StatusCode::SWITCHING_PROTOCOLS in response
     let upgrade_in_response = extract_upgrade(res_backend.headers());
     let should_upgrade = match (upgrade_in_request.as_ref(), upgrade_in_response.as_ref()) {
-      (Some(u_req), Some(u_res)) => u_req.to_ascii_lowercase() == u_res.to_ascii_lowercase(),
+      (Some(u_req), Some(u_res)) => u_req.eq_ignore_ascii_case(u_res),
       _ => false,
     };
 
diff --git a/rpxy-lib/src/message_handler/utils_headers.rs b/rpxy-lib/src/message_handler/utils_headers.rs
index d058f88..1fa3c99 100644
--- a/rpxy-lib/src/message_handler/utils_headers.rs
+++ b/rpxy-lib/src/message_handler/utils_headers.rs
@@ -272,7 +272,7 @@ pub(super) fn extract_upgrade(headers: &HeaderMap) -> Option<String> {
       .to_str()
       .unwrap_or("")
       .split(',')
-      .any(|w| w.trim().to_ascii_lowercase() == header::UPGRADE.as_str().to_ascii_lowercase())
+      .any(|w| w.trim().eq_ignore_ascii_case(header::UPGRADE.as_str()))
     {
       if let Some(u) = headers.get(header::UPGRADE) {
         if let Ok(m) = u.to_str() {