Is there any difference of dihedral angle energy formula between PCFF and COMPASS?

The dihedral angle energy formula for COMPASS is k(n)*(1-cos(n*phi-phi(n))), but, for PCFF, k(n)*(1+cos(n*phi-phi(n))) as written in pcff.frc.

I checked some representative dihedral angle types, but their coffecients are almost same for both force fields.

In this case, the dihedral angle energy is opposite.

I think the formula in pcff.frc is typo.. am I right?