I wrote a jade file as shown below:

```
extends layout

block content
  h1= title
  p Welcome 123 to #{title}

block scripts
  script(src='/socket.io/socket.io.js')
  script(src='/javascripts/client.js')

```

However when I run I get the following Warning: `Warning: Unexpected block "scripts" This block is never used. This warning will be an error in v2.0.0`

My Package.json file has jade version `~1.9.0`

However this works when Jade version is `~1.8.2`

What could be the problem?