diff --git a/README.markdown b/README.markdown
index 24e11ce..b5d9b4f 100644
--- a/README.markdown
+++ b/README.markdown
@@ -25,7 +25,7 @@ apns.gateway_server.send_notification(token_hex, payload)
 # Send multiple notifications in a single transmission
 frame = Frame()
 identifier = 1
-expiry = time.time()+3600
+expiry = int(time.time()+3600)
 priority = 10
 frame.add_item('b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b87', payload, identifier, expiry, priority)
 apns.gateway_server.send_notification_multiple(frame)