README.md in sentry-raven-3.0.4 vs README.md in sentry-raven-3.1.0

- old
+ new

@@ -103,11 +103,11 @@
 #### transport_failure_callback
 
 If Raven fails to send an event to Sentry for any reason (either the Sentry server has returned a 4XX or 5XX response), this Proc or lambda will be called.
 
 ```ruby
-config.transport_failure_callback = lambda { |event|
-  AdminMailer.email_admins("Oh god, it's on fire!", event).deliver_later
+config.transport_failure_callback = lambda { |event, error|
+  AdminMailer.email_admins("Oh god, it's on fire because #{error.message}!", event).deliver_later
 }
 ```
 
 #### Context
 