diff --git a/io/vmess/vmess.go b/io/vmess/vmess.go
index 2f5ff895..ca02f3db 100644
--- a/io/vmess/vmess.go
+++ b/io/vmess/vmess.go
@@ -226,10 +226,7 @@ func (w *VMessRequestWriter) Write(writer io.Writer, request *VMessRequest) erro
 		buffer = append(buffer, []byte(request.Address.Domain)...)
 	}
 
-	paddingLength := blockSize - 1 - (len(buffer)-encryptionBegin)%blockSize
-	if paddingLength == 0 {
-		paddingLength = blockSize
-	}
+	paddingLength := mrand.Intn(32) + 1
 	paddingBuffer := make([]byte, paddingLength)
 	_, err = rand.Read(paddingBuffer)
 	if err != nil {
diff --git a/spec/vmess.md b/spec/vmess.md
index bc17ec12..e432249e 100644
--- a/spec/vmess.md
+++ b/spec/vmess.md
@@ -26,7 +26,7 @@
   * 4 字节：IPv4
   * 1 字节长度 + 域名
   * 16 字节：IPv6
-* 1 字节：随机填充长度 M2 (0 < M2 <= 32)，使得指令部分长度为 16 的倍数字节
+* 1 字节：随机填充长度 M2 (0 < M2 <= 32)
 * M2 字节：随机填充内容
 
 数据部分