diff --git a/ch12_mining.adoc b/ch12_mining.adoc
index 4e9e01cf..4ad94149 100644
--- a/ch12_mining.adoc
+++ b/ch12_mining.adoc
@@ -1583,7 +1583,7 @@ Security research groups have used statistical modeling to claim that
 various types of hashrate attacks are possible with as little as 30% of
 the hashing power.
 
-The centralization of control caused by mining pools has
+The centralization of control ((("mining pools")))caused by mining pools has
 introduced the risk of for-profit attacks by a mining pool operator. The
 pool operator in a managed pool controls the construction of candidate
 blocks and also controls which transactions are included. This gives the