diff --git a/ch04_keys.adoc b/ch04_keys.adoc
index 1b158c5e..001fbc2d 100644
--- a/ch04_keys.adoc
+++ b/ch04_keys.adoc
@@ -651,7 +651,7 @@ the wallet software as a valid destination, an error that would
 otherwise result in loss of funds.
 
 To convert data (a number) into a base58check format, we first add a
-prefix to the data, called the "version byte," which serves to easily
+prefix to the data, called ((("version prefix")))the "version byte," which serves to easily
 identify the type of data that is encoded. For example, the prefix zero
 (0x00 in hex) indicates that the data should be used as the commitment (hash) in
 a legacy P2PKH output script.  A list of common version prefixes is shown