diff --git a/Server-Query-Protocol.md b/Server-Query-Protocol.md
index 405157e..59747e8 100644
--- a/Server-Query-Protocol.md
+++ b/Server-Query-Protocol.md
@@ -33,8 +33,8 @@ The checksum function used is a variant of CRC16:
 ```
 u16 x;
 u16 crc = 0xFFFF;
-for (u32 i = 0; i < buf.wp; ++i) {
-  x = crc >> 8 ^ buf.data[i];
+for (u32 i = 0; i < numbytes; ++i) {
+  x = crc >> 8 ^ bytes[i];
   x ^= x >> 4;
   crc += (crc << 8) ^ (x << 12) ^ (x << 5) ^ x;
 }