How to set indent size of .html.erb file?

I'm using IntelliJ IDEA 13.0.2 with Ruby plugin.

I want to set indent size of .html.erb file.

I tried to open Settings dialog and select "Code Style - General", "Code Style - Ruby", "Code Style - HTML" and set "Indent" and "Continuation indent" to "2", but It seems not to work well; 4 spaces are inserted after inputing "<p>" and enter key.

How to set it?