diff --git a/ch11_blockchain.adoc b/ch11_blockchain.adoc
index 8e25c2f0..5e235443 100644
--- a/ch11_blockchain.adoc
+++ b/ch11_blockchain.adoc
@@ -705,7 +705,7 @@ Core that's only designed to run on signet.
 
 If you want to use a different signet, called a _custom signet_, you
 will need to know the script used to determine when a block is
-authorized, called the _challenge_ script.  This is a standard Bitcoin
+authorized, called((("challenge script"))) the _challenge_ script.  This is a standard Bitcoin
 script, so it can use features such as multisig to allow multiple people
 to authorize blocks.  You may also need to connect to a seed node that
 will provide you with the addresses of peers on the custom signet.  For