diff --git a/apps/csms/src/index.ts b/apps/csms/src/index.ts
index b6b03ac..870aee0 100644
--- a/apps/csms/src/index.ts
+++ b/apps/csms/src/index.ts
@@ -85,12 +85,8 @@ app.get(
   '/ocpp/:chargePointId',
   upgradeWebSocket((c) => {
     const chargePointId = c.req.param('chargePointId')
-    if (!chargePointId) {
-      throw new Error('Missing chargePointId route param')
-    }
     const connInfo = getConnInfo(c)
-    const requestedProtocol = c.req.header('sec-websocket-protocol')
-    return createOcppHandler(chargePointId, connInfo.remote.address, requestedProtocol)
+    return createOcppHandler(chargePointId, connInfo.remote.address)
   }),
 )
 
diff --git a/apps/csms/src/ocpp/handler.ts b/apps/csms/src/ocpp/handler.ts
index 5a96980..dfe2988 100644
--- a/apps/csms/src/ocpp/handler.ts
+++ b/apps/csms/src/ocpp/handler.ts
@@ -92,26 +92,6 @@ function sendCallError(
   )
 }
 
-function pickOcppSubprotocol(
-  negotiatedProtocol?: string | null,
-  requestedHeader?: string | null,
-) {
-  if (negotiatedProtocol && isSupportedOCPP(negotiatedProtocol)) {
-    return negotiatedProtocol
-  }
-
-  if (!requestedHeader) {
-    return null
-  }
-
-  const requestedProtocols = requestedHeader
-    .split(',')
-    .map((value) => value.trim())
-    .filter(Boolean)
-
-  return requestedProtocols.find((protocol) => isSupportedOCPP(protocol)) ?? null
-}
-
 /**
  * Factory that produces a hono-ws event handler object for a single
  * OCPP WebSocket connection.
@@ -119,11 +99,7 @@ function pickOcppSubprotocol(
  * Usage in route:
  *   upgradeWebSocket((c) => createOcppHandler(c.req.param('chargePointId'), remoteAddr))
  */
-export function createOcppHandler(
-  chargePointIdentifier: string,
-  remoteAddr?: string,
-  requestedProtocolHeader?: string,
-) {
+export function createOcppHandler(chargePointIdentifier: string, remoteAddr?: string) {
   const ctx: OcppConnectionContext = {
     chargePointIdentifier,
     isRegistered: false,
@@ -131,14 +107,14 @@ export function createOcppHandler(
 
   return {
     onOpen(_evt: Event, ws: WSContext) {
-      const subProtocol = pickOcppSubprotocol(ws.protocol, requestedProtocolHeader)
-      if (!subProtocol) {
+      const subProtocol = ws.protocol ?? 'unknown'
+      if (!isSupportedOCPP(subProtocol)) {
         ws.close(1002, 'Unsupported subprotocol')
         return
       }
       ocppConnections.set(chargePointIdentifier, ws)
       console.log(
-        `[OCPP] ${chargePointIdentifier} connected (${subProtocol})` +
+        `[OCPP] ${chargePointIdentifier} connected` +
           (remoteAddr ? ` from ${remoteAddr}` : ''),
       )
     },
diff --git a/hardware/firmware/lib/mongoose/mongoose_config.h b/hardware/firmware/lib/mongoose/mongoose_config.h
index e540434..910630d 100644
--- a/hardware/firmware/lib/mongoose/mongoose_config.h
+++ b/hardware/firmware/lib/mongoose/mongoose_config.h
@@ -1,2 +1 @@
 #define MG_ARCH MG_ARCH_ESP32
-#define MG_TLS MG_TLS_MBED // Use ESP-IDF built-in mbedTLS for WSS support