diff --git a/mercurial/help/internals/bundle2.txt b/mercurial/help/internals/bundle2.txt
--- a/mercurial/help/internals/bundle2.txt
+++ b/mercurial/help/internals/bundle2.txt
@@ -61,7 +61,7 @@ options should go into a bundle2 part in
 
 The following stream level parameters are defined:
 
-compression
+Compression
    Compression format of payload data. ``GZ`` denotes zlib. ``BZ``
    denotes bzip2. ``ZS`` denotes zstandard.