2.3 gingerbread - Disable automatic screen turn-off during call

I use Gingerbread.

My Android phone has feature, that turns off display during call when I put the phone to my ear. However, the sensor is probably over-sensitive in my device, so it often turns off during call even when I don't keep it next to my face.

This is an issue if I want to use keyboard during call when the screen turns off. Can I disable this feature?