diff --git a/README.txt b/README.txt
--- a/README.txt
+++ b/README.txt
@@ -125,7 +125,7 @@ time, also without saving the password.
 
 Finally, if you are consistent about remote repository nicknames,
 you can configure the username in your `~/.hgrc` (`.hgrc` in your
-home directory). For example, write there:
+home directory). For example, write there::
 
     [auth]
     acme.prefix = hg.acme.com/repositories