diff --git a/docs/protocol.md b/docs/protocol.md
index 8f48d15..f46aa80 100644
--- a/docs/protocol.md
+++ b/docs/protocol.md
@@ -278,9 +278,10 @@ The gateway assigns a distinct non-zero `site_id` to each side and rewrites `sit
 `str8` — a length-prefixed UTF-8 string, not NUL-terminated on the wire:
 
 ```mermaid
+%%{init: {'packet': {'bitsPerRow': 8}}}%%
 packet-beta
 0-7: "length"
-8-39: "bytes (≤ 255) …"
+8-15: "data (≤ 255 bytes)"
 ```
 
 Maximum string length is 255 bytes.