diff --git a/adapter/v2ray.go b/adapter/v2ray.go
index df6372a1..d1b420ee 100644
--- a/adapter/v2ray.go
+++ b/adapter/v2ray.go
@@ -5,7 +5,6 @@ import (
 	"net"
 
 	E "github.com/sagernet/sing/common/exceptions"
-	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
 )
 
@@ -19,7 +18,6 @@ type V2RayServerTransport interface {
 type V2RayServerTransportHandler interface {
 	N.TCPConnectionHandler
 	E.Handler
-	FallbackConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error
 }
 
 type V2RayClientTransport interface {
diff --git a/inbound/trojan.go b/inbound/trojan.go
index 84ef9bcf..82432131 100644
--- a/inbound/trojan.go
+++ b/inbound/trojan.go
@@ -227,10 +227,3 @@ func (t *trojanTransportHandler) NewConnection(ctx context.Context, conn net.Con
 		Destination: metadata.Destination,
 	})
 }
-
-func (t *trojanTransportHandler) FallbackConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
-	return (*Trojan)(t).fallbackConnection(ctx, conn, adapter.InboundContext{
-		Source:      metadata.Source,
-		Destination: metadata.Destination,
-	})
-}
diff --git a/inbound/vless.go b/inbound/vless.go
index efb73551..11df86bf 100644
--- a/inbound/vless.go
+++ b/inbound/vless.go
@@ -189,7 +189,3 @@ func (t *vlessTransportHandler) NewConnection(ctx context.Context, conn net.Conn
 		Destination: metadata.Destination,
 	})
 }
-
-func (t *vlessTransportHandler) FallbackConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
-	return os.ErrInvalid
-}
diff --git a/inbound/vmess.go b/inbound/vmess.go
index 89f938fc..77a8b28a 100644
--- a/inbound/vmess.go
+++ b/inbound/vmess.go
@@ -198,7 +198,3 @@ func (t *vmessTransportHandler) NewConnection(ctx context.Context, conn net.Conn
 		Destination: metadata.Destination,
 	})
 }
-
-func (t *vmessTransportHandler) FallbackConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
-	return os.ErrInvalid
-}
diff --git a/transport/v2raygrpclite/server.go b/transport/v2raygrpclite/server.go
index bcf55def..a3025ca6 100644
--- a/transport/v2raygrpclite/server.go
+++ b/transport/v2raygrpclite/server.go
@@ -64,15 +64,15 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 		return
 	}
 	if request.URL.Path != s.path {
-		s.fallbackRequest(request.Context(), writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
+		s.invalidRequest(writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
 		return
 	}
 	if request.Method != http.MethodPost {
-		s.fallbackRequest(request.Context(), writer, request, http.StatusNotFound, E.New("bad method: ", request.Method))
+		s.invalidRequest(writer, request, http.StatusNotFound, E.New("bad method: ", request.Method))
 		return
 	}
 	if ct := request.Header.Get("Content-Type"); !strings.HasPrefix(ct, "application/grpc") {
-		s.fallbackRequest(request.Context(), writer, request, http.StatusNotFound, E.New("bad content type: ", ct))
+		s.invalidRequest(writer, request, http.StatusNotFound, E.New("bad content type: ", ct))
 		return
 	}
 	writer.Header().Set("Content-Type", "application/grpc")
@@ -85,18 +85,11 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	conn.CloseWrapper()
 }
 
-func (s *Server) fallbackRequest(ctx context.Context, writer http.ResponseWriter, request *http.Request, statusCode int, err error) {
-	conn := v2rayhttp.NewHTTPConn(request.Body, writer)
-	fErr := s.handler.FallbackConnection(ctx, &conn, M.Metadata{})
-	if fErr == nil {
-		return
-	} else if fErr == os.ErrInvalid {
-		fErr = nil
-	}
+func (s *Server) invalidRequest(writer http.ResponseWriter, request *http.Request, statusCode int, err error) {
 	if statusCode > 0 {
 		writer.WriteHeader(statusCode)
 	}
-	s.handler.NewError(request.Context(), E.Cause(E.Errors(err, E.Cause(fErr, "fallback connection")), "process connection from ", request.RemoteAddr))
+	s.handler.NewError(request.Context(), E.Cause(err, "process connection from ", request.RemoteAddr))
 }
 
 func (s *Server) Serve(listener net.Listener) error {
diff --git a/transport/v2rayhttp/server.go b/transport/v2rayhttp/server.go
index 962f0ab1..a635e8f3 100644
--- a/transport/v2rayhttp/server.go
+++ b/transport/v2rayhttp/server.go
@@ -85,15 +85,15 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	}
 	host := request.Host
 	if len(s.host) > 0 && !common.Contains(s.host, host) {
-		s.fallbackRequest(request.Context(), writer, request, http.StatusBadRequest, E.New("bad host: ", host))
+		s.invalidRequest(writer, request, http.StatusBadRequest, E.New("bad host: ", host))
 		return
 	}
 	if !strings.HasPrefix(request.URL.Path, s.path) {
-		s.fallbackRequest(request.Context(), writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
+		s.invalidRequest(writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
 		return
 	}
 	if request.Method != s.method {
-		s.fallbackRequest(request.Context(), writer, request, http.StatusNotFound, E.New("bad method: ", request.Method))
+		s.invalidRequest(writer, request, http.StatusNotFound, E.New("bad method: ", request.Method))
 		return
 	}
 
@@ -113,7 +113,7 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 			requestBody = buf.NewSize(contentLength)
 			_, err := requestBody.ReadFullFrom(request.Body, contentLength)
 			if err != nil {
-				s.fallbackRequest(request.Context(), writer, request, 0, E.Cause(err, "read request"))
+				s.invalidRequest(writer, request, 0, E.Cause(err, "read request"))
 				return
 			}
 		}
@@ -121,14 +121,15 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 		writer.(http.Flusher).Flush()
 		conn, reader, err := h.Hijack()
 		if err != nil {
-			s.fallbackRequest(request.Context(), writer, request, 0, E.Cause(err, "hijack conn"))
+			s.invalidRequest(writer, request, 0, E.Cause(err, "hijack conn"))
 			return
 		}
 		if cacheLen := reader.Reader.Buffered(); cacheLen > 0 {
 			cache := buf.NewSize(cacheLen)
 			_, err = cache.ReadFullFrom(reader.Reader, cacheLen)
 			if err != nil {
-				s.fallbackRequest(request.Context(), writer, request, 0, E.Cause(err, "read cache"))
+				conn.Close()
+				s.invalidRequest(writer, request, 0, E.Cause(err, "read cache"))
 				return
 			}
 			conn = bufio.NewCachedConn(conn, cache)
@@ -148,18 +149,11 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	}
 }
 
-func (s *Server) fallbackRequest(ctx context.Context, writer http.ResponseWriter, request *http.Request, statusCode int, err error) {
-	conn := NewHTTPConn(request.Body, writer)
-	fErr := s.handler.FallbackConnection(ctx, &conn, M.Metadata{})
-	if fErr == nil {
-		return
-	} else if fErr == os.ErrInvalid {
-		fErr = nil
-	}
+func (s *Server) invalidRequest(writer http.ResponseWriter, request *http.Request, statusCode int, err error) {
 	if statusCode > 0 {
 		writer.WriteHeader(statusCode)
 	}
-	s.handler.NewError(request.Context(), E.Cause(E.Errors(err, E.Cause(fErr, "fallback connection")), "process connection from ", request.RemoteAddr))
+	s.handler.NewError(request.Context(), E.Cause(err, "process connection from ", request.RemoteAddr))
 }
 
 func (s *Server) Serve(listener net.Listener) error {
diff --git a/transport/v2raywebsocket/server.go b/transport/v2raywebsocket/server.go
index 73bf56ff..9d8bc69a 100644
--- a/transport/v2raywebsocket/server.go
+++ b/transport/v2raywebsocket/server.go
@@ -12,7 +12,6 @@ import (
 	"github.com/sagernet/sing-box/common/tls"
 	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/option"
-	"github.com/sagernet/sing-box/transport/v2rayhttp"
 	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/buf"
 	"github.com/sagernet/sing/common/bufio"
@@ -69,7 +68,7 @@ var upgrader = websocket.Upgrader{
 func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	if s.maxEarlyData == 0 || s.earlyDataHeaderName != "" {
 		if request.URL.Path != s.path {
-			s.fallbackRequest(request.Context(), writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
+			s.invalidRequest(writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
 			return
 		}
 	}
@@ -83,7 +82,7 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 			earlyDataStr := request.URL.RequestURI()[len(s.path):]
 			earlyData, err = base64.RawURLEncoding.DecodeString(earlyDataStr)
 		} else {
-			s.fallbackRequest(request.Context(), writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
+			s.invalidRequest(writer, request, http.StatusNotFound, E.New("bad path: ", request.URL.Path))
 			return
 		}
 	} else {
@@ -93,12 +92,12 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 		}
 	}
 	if err != nil {
-		s.fallbackRequest(request.Context(), writer, request, http.StatusBadRequest, E.Cause(err, "decode early data"))
+		s.invalidRequest(writer, request, http.StatusBadRequest, E.Cause(err, "decode early data"))
 		return
 	}
 	wsConn, err := upgrader.Upgrade(writer, request, nil)
 	if err != nil {
-		s.fallbackRequest(request.Context(), writer, request, 0, E.Cause(err, "upgrade websocket connection"))
+		s.invalidRequest(writer, request, 0, E.Cause(err, "upgrade websocket connection"))
 		return
 	}
 	var metadata M.Metadata
@@ -110,18 +109,11 @@ func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	s.handler.NewConnection(request.Context(), conn, metadata)
 }
 
-func (s *Server) fallbackRequest(ctx context.Context, writer http.ResponseWriter, request *http.Request, statusCode int, err error) {
-	conn := v2rayhttp.NewHTTPConn(request.Body, writer)
-	fErr := s.handler.FallbackConnection(ctx, &conn, M.Metadata{})
-	if fErr == nil {
-		return
-	} else if fErr == os.ErrInvalid {
-		fErr = nil
-	}
+func (s *Server) invalidRequest(writer http.ResponseWriter, request *http.Request, statusCode int, err error) {
 	if statusCode > 0 {
 		writer.WriteHeader(statusCode)
 	}
-	s.handler.NewError(request.Context(), E.Cause(E.Errors(err, E.Cause(fErr, "fallback connection")), "process connection from ", request.RemoteAddr))
+	s.handler.NewError(request.Context(), E.Cause(err, "process connection from ", request.RemoteAddr))
 }
 
 func (s *Server) Network() []string {