diff --git a/ch03_bitcoin-core.adoc b/ch03_bitcoin-core.adoc
index 5e99cdb2..b351b36e 100644
--- a/ch03_bitcoin-core.adoc
+++ b/ch03_bitcoin-core.adoc
@@ -794,7 +794,7 @@ e739df2f899c49dc267c0ad280aca6dab0d2fa2b42a45182fc83e81713010000
 [TIP]
 ====
 A transaction ID (txid)
-is not authoritative. Absence of a txid in the blockchain does not mean
+is ((("transaction IDs (txid)")))not authoritative. Absence of a txid in the blockchain does not mean
 the transaction was not processed. This is known as "transaction
 malleability," because transactions can be modified prior to
 confirmation in a block, changing their txids.  After a transaction is