diff --git a/ch09.asciidoc b/ch09.asciidoc
index c326011e..6eae1af9 100644
--- a/ch09.asciidoc
+++ b/ch09.asciidoc
@@ -72,7 +72,7 @@ A block's _block hash_ always identifies a single block uniquely. A block also a
 
 Every node always starts with a blockchain of at least one block because the genesis block is statically encoded within the bitcoin client software, such that it cannot be altered. Every node always "knows" the genesis block's hash and structure, the fixed time it was created, and even the single transaction within. Thus, every node has the starting point for the blockchain, a secure "root" from which to build a trusted blockchain.
 
-See the statically encoded genesis block inside the Bitcoin Core client, in http://bit.ly/1x6rcwP[chainparams.cpp].
+See the statically encoded genesis block inside the Bitcoin Core client, in http://bit.ly/1x6rcwP[_chainparams.cpp_].
 
 [role="pagebreak-before"]
 The following identifier hash belongs to the genesis block: