diff --git a/preface.asciidoc b/preface.asciidoc
index 8e490082..a1f5c26f 100644
--- a/preface.asciidoc
+++ b/preface.asciidoc
@@ -131,7 +131,7 @@ blockchain::
 	
 confirmations::
 ((("confirmations")))
-		Once a transaction is included in a block, it has "one confirmation". As soon as _another_ block is mined on the same blockchain, the transaction has two confirmations etc. Six or more confirmations is considered final. 
+		Once a transaction is included in a block, it has "one confirmation". As soon as _another_ block is mined on the same blockchain, the transaction has two confirmations etc. Six or more confirmations is considered sufficient proof that a transaction can not be reversed.
 
 difficulty::
 ((("difficulty")))