Adding -std=c++11 to compiler options in Anjuta

I'm fairly far in a project using GTKmm atm, and I'm trying to add in some code a friend of mine have been working on. However I'm getting this error:

error This file requires compiler and library support for the ISO C++ 2011 standard. This support is currently experimental, and must be enabled with the -std=c++11 or -std=gnu++11 compiler options

However I can't find anywhere that will actually let me add these compiler options.

Adding it to Build -> Configure Project only yields a: Error: unrecognized option 'std=c++11'.

Anyone more familiar with this IDE who might be able to help?