diff --git a/common/protocol/errors.go b/common/protocol/errors.go
deleted file mode 100644
index a0ff515b..00000000
--- a/common/protocol/errors.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package protocol
-
-import (
-	"v2ray.com/core/common/errors"
-)
-
-var (
-	ErrInvalidUser    = errors.New("Invalid user.")
-	ErrInvalidVersion = errors.New("Invalid version.")
-)
diff --git a/proxy/vmess/encoding/server.go b/proxy/vmess/encoding/server.go
index 8fbb65ed..ff550185 100644
--- a/proxy/vmess/encoding/server.go
+++ b/proxy/vmess/encoding/server.go
@@ -58,7 +58,7 @@ func (v *ServerSession) DecodeRequestHeader(reader io.Reader) (*protocol.Request
 
 	user, timestamp, valid := v.userValidator.Get(buffer[:protocol.IDBytesLen])
 	if !valid {
-		return nil, protocol.ErrInvalidUser
+		return nil, errors.New("VMess|Server: Invalid user.")
 	}
 
 	timestampHash := md5.New()