diff --git a/doc/dev/rbd-diff.rst b/doc/dev/rbd-diff.rst
index c9729cbae81..77a9a35d4c6 100644
--- a/doc/dev/rbd-diff.rst
+++ b/doc/dev/rbd-diff.rst
@@ -7,8 +7,7 @@ two snapshots (or a snapshot and the head) of an RBD image.
 Header
 ------
 
-le32: string length, always 13
-"rbd diff v1"
+"rbd diff v1\n"
 
 Record
 ------
@@ -51,6 +50,11 @@ u8: 'z'
 le64: offset
 le64: length
 
+End
+---
+
+u8: 'e'
+