diff --git a/ch04_keys.adoc b/ch04_keys.adoc
index 684466c7..fdd41a7b 100644
--- a/ch04_keys.adoc
+++ b/ch04_keys.adoc
@@ -757,7 +757,7 @@ encoding, <<pubkey_to_address>> illustrates the conversion of a public key
 into a Bitcoin ((("public key cryptography", "base58check encoding", startref="pub-key-base58")))((("base58check encoding", startref="base58-ch4")))((("encoding", "base58check", startref="encode-base58")))((("version prefixes", startref="version-prefix")))address.
 
 [[pubkey_to_address]]
-.Public key to Bitcoin address: conversion of a public key into a Bitcoin address
+.Public key to Bitcoin address: conversion of a public key to a Bitcoin address
 image::images/mbc3_0407.png["pubkey_to_address"]
 
 [[comp_pub]]