diff --git a/tpmutil/mssim/mssim.go b/tpmutil/mssim/mssim.go
index 2ec05e54..17fe20a7 100644
--- a/tpmutil/mssim/mssim.go
+++ b/tpmutil/mssim/mssim.go
@@ -172,12 +172,15 @@ func (c *Conn) Write(b []byte) (int, error) {
 	buff.WriteByte(0)
 	// size of the command
 	binary.Write(buff, binary.BigEndian, uint32(len(b)))
-	// raw command
-	buff.Write(b)
 
 	if _, err := buff.WriteTo(c.conn); err != nil {
 		return 0, fmt.Errorf("write MS simulator command: %v", err)
 	}
+	// The raw command is transmitted separately. Easy to analyze in wireshark.
+	// https://github.com/google/go-tpm/pull/339
+	if _, err := c.conn.Write(b); err != nil {
+		return 0, fmt.Errorf("write MS simulator command: %v", err)
+	}
 	return len(b), nil
 }