Can't change the multiplier on my 4670k with my msi g45-z87 gaming?

[Gluggle]

Trying to overclock my 4670k and whenever I go into bios I can't change the multiplier or 'ratio'? It's greyed out and unclickable, the only thing I can change is the base clock(which can only go down either way) and voltage.

 

[Stysner]

It's locked. There should be an option (most BIOS'es have it at the top of the CPU settings) to set the CPU in manual mode instead of auto. It's locked by default so people don't accidentally change the voltage to a dangerous level in the BIOS.