diff --git a/book/source/02-highlevel.md b/book/source/02-highlevel.md
index 4b18a21..6c94707 100644
--- a/book/source/02-highlevel.md
+++ b/book/source/02-highlevel.md
@@ -61,7 +61,7 @@ The following statement does not make sense here in the history part.
 In 2007, the IETF published [RFC 4880](https://datatracker.ietf.org/doc/html/rfc4880), which defined version 4 of the OpenPGP standard. At this time, version 4 is the most commonly used version.
 
 
-### Multiple major implementations
+### Major implementations m of OpenPGP
 
 Today, multiple implementations of OpenPGP play important roles: