diff --git a/protocol.md b/protocol.md
index 2949f3a..56f2165 100644
--- a/protocol.md
+++ b/protocol.md
@@ -101,5 +101,5 @@ Two wire UART 115200 8n1
 | 61 | ofs | bReadLen, bHeadDataLen, bHeadData[bHeadDataLen] | - | + | - | All | 01 ofs data[] | Read regs, update head inputs |
 | 64 | any | bDataLen, bThrottle, bBrake, wUnkn [, wBLEFwVersion] | - | + | - | ? | All | Update head inputs |
 | 64 | any | bDataLen, bFlags, bBattLevelBars, bHeadlightLevel, bBeeps | + | - | - | ? | M365 | Update head outputs |
-| 64 | any | bDataLen, bFlags, bBattLevelBars, bHeadlightLevel, bBeeps, wSpeed | + | - | - | ? | M365 Pro | Update head outputs |
+| 64 | any | bDataLen, bFlags, bBattLevelBars, bHeadlightLevel, bBeeps, bSpeed, bErrorCode | + | - | - | ? | Ninebot, M365 Pro | Update head outputs |
 | 65 | any | bDataLen, bThrottle, bBrake, wUnkn [, wBLEFwVersion] | - | + | - | ? | All | Update head inputs |