How to disable narrowing conversion warnings?

I use -Wall and updating to new gcc I have got a lot of warning: narrowing conversion. I want to disable them, but leave all other warnings untouched (ideally).

I can find nothing about narrowing in http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html

How to disable narrowing conversion warnings?Is it possible at all?

P.S.

1. I need to Disable warnings, not fix them in the source code.

2. Blind -Wno-conversion doesn't help.