iPhone My proximity Sensor is Dead, is there a tweak that can help?

My proximity sensor isn't working anymore...so when I make a call, the screen stays on. I had an android phone taht this happened to once, and I could just use the power button to shut the screen off, but that just ends the call on an iphone.

It doesn't look like there is an option in Activator...does anyone have an idea how I can change the function of the power button during a call??? Thanks!