diff --git a/preface.asciidoc b/preface.asciidoc
index be3af5da..c114b0fc 100644
--- a/preface.asciidoc
+++ b/preface.asciidoc
@@ -190,7 +190,7 @@ bip::
 
 bitcoin::
 ((("bitcoin"))) 
-    The name of the currency unit (the coin), the network and the software
+    The name of the currency unit (the coin), the network, and the software.
 
 block::
 ((("block")))