How to get Terrain to respect shader offset

I have tried just about everything I can think of to try to get terrain to respect another shader having an offset, but I still get z-fighting between them. The I'm using avoids z-fighting with everything else, but somehow, even if I replace the terrain shader with a basic one with nothing except a offset away from the camera AND a modified ztest, I still constantly get z-fighting. Does anyone know a fix for this? And no, moving the other shape above the terrain is not a viable option.