diff --git a/ch04.asciidoc b/ch04.asciidoc
index 22ad3ec0..1bf2d812 100644
--- a/ch04.asciidoc
+++ b/ch04.asciidoc
@@ -245,7 +245,7 @@ where K is the public key and A is the resulting bitcoin address.
 A bitcoin address is _not_ the same as a public key. Bitcoin addresses are derived from a public key using a one-way function. 
 ====
 
-Bitcoin addresses are almost always presented to users in an encoding called "Base58Check" (see <<base58check>>), which uses 58 characters (a Base58 number system) and a checksum to help human readability, avoid ambiguity, and protect against errors in address transcription and entry. Base58Check is also used in many other ways in bitcoin, whenever there is a need for a user to read and correctly transcribe a number, such as a bitcoin address, a private key, an encrypted key, or a script hash. In the next section we will examine the mechanics of Base58Check encoding and decoding, and the resulting representations. <<pubkey_to_adddress>> illustrates the conversion of a public key into a bitcoin address.
+Bitcoin addresses are almost always presented to users in an encoding called "Base58Check", which uses 58 characters (a Base58 number system) and a checksum to help human readability, avoid ambiguity, and protect against errors in address transcription and entry. Base58Check is also used in many other ways in bitcoin, whenever there is a need for a user to read and correctly transcribe a number, such as a bitcoin address, a private key, an encrypted key, or a script hash. In the next section we will examine the mechanics of Base58Check encoding and decoding, and the resulting representations. <<pubkey_to_adddress>> illustrates the conversion of a public key into a bitcoin address.
 
 [[pubkey_to_adddress]]
 .Public key to bitcoin address: conversion of a public key into a bitcoin address