diff --git a/websocket/src/handshake.cpp b/websocket/src/handshake.cpp
index ed81461..2f2f7e4 100644
--- a/websocket/src/handshake.cpp
+++ b/websocket/src/handshake.cpp
@@ -66,6 +66,12 @@ static Result SendClientHandshakeHeaders(WebsocketConnection* conn)
         }
     }
 
+    if (conn->m_Protocol) {
+        WS_SENDALL("Sec-WebSocket-Protocol: ");
+        WS_SENDALL(conn->m_Protocol);
+        WS_SENDALL("\r\n");
+    }
+
     WS_SENDALL("\r\n");
 
 bail:
@@ -114,7 +120,7 @@ Result ReceiveHeaders(WebsocketConnection* conn)
     {
         if (dmSocket::RESULT_WOULDBLOCK)
         {
-            DebugLog(1, "Waiting for socket to be available for reading");
+            DebugLog(2, "Waiting for socket to be available for reading");
             return RESULT_WOULDBLOCK;
         }
 
@@ -197,9 +203,6 @@ Result VerifyHeaders(WebsocketConnection* conn)
     bool connection = false;
     bool upgrade = false;
     bool valid_key = false;
-    const char* protocol = "";
-
-    // TODO: Perhaps also support the Sec-WebSocket-Protocol
 
     // parse the headers in place
     while (r < endtag)
diff --git a/websocket/src/websocket.cpp b/websocket/src/websocket.cpp
index 38ab469..6df1c9d 100644
--- a/websocket/src/websocket.cpp
+++ b/websocket/src/websocket.cpp
@@ -212,6 +212,7 @@ static void DestroyConnection(WebsocketConnection* conn)
 #endif
 
     free((void*)conn->m_CustomHeaders);
+    free((void*)conn->m_Protocol);
 
     if (conn->m_Callback)
         dmScript::DestroyCallback(conn->m_Callback);
@@ -271,6 +272,7 @@ static int LuaConnect(lua_State* L)
     const char* url = luaL_checkstring(L, 1);
     lua_Number timeout = dmScript::CheckTableNumber(L, 2, "timeout", 3000);
     const char* custom_headers = dmScript::CheckTableString(L, 2, "headers", 0);
+    const char* protocol = dmScript::CheckTableString(L, 2, "protocol", 0);
 
     if (custom_headers != 0)
     {
@@ -283,6 +285,7 @@ static int LuaConnect(lua_State* L)
     WebsocketConnection* conn = CreateConnection(url);
     conn->m_ConnectTimeout = dmTime::GetTime() + timeout * 1000;
     conn->m_CustomHeaders = custom_headers ? strdup(custom_headers) : 0;
+    conn->m_Protocol = protocol ? strdup(protocol) : 0;
 
     conn->m_Callback = dmScript::CreateCallback(L, 3);
 
@@ -709,6 +712,13 @@ static dmExtension::Result OnUpdate(dmExtension::Params* params)
 #if defined(__EMSCRIPTEN__)
             conn->m_SSLSocket = dmSSLSocket::INVALID_SOCKET_HANDLE;
 
+            if (conn->m_Protocol) {
+                EM_ASM({
+                    // https://emscripten.org/docs/porting/networking.html#emulated-posix-tcp-sockets-over-websockets
+                    Module["websocket"]["subprotocol"] = UTF8ToString($0);
+                }, conn->m_Protocol);
+            }
+
             char uri_buffer[dmURI::MAX_URI_LEN];
             const char* uri;
             if (conn->m_Url.m_Path[0] != '\0') {
diff --git a/websocket/src/websocket.h b/websocket/src/websocket.h
index 156c6a4..9464f4b 100644
--- a/websocket/src/websocket.h
+++ b/websocket/src/websocket.h
@@ -91,6 +91,7 @@ namespace dmWebsocket
         dmArray<Message>                m_Messages; // lengths of the messages in the data buffer
         uint64_t                        m_ConnectTimeout;
         uint8_t                         m_Key[16];
+        const char*                     m_Protocol;
         const char*                     m_CustomHeaders;
         State                           m_State;
         char*                           m_Buffer;