Runge‐Kutta (RK) pairs sharing orders 6 and 5 are widely used for solving initial value problems. Thus, we consider the dispersion from a standard cyclic orbit as a function of frequency v and present a modification of a particular pair. Namely, we derive a zero‐dissipative pair with vanished phase lag and its first derivative. This modified pair outperforms the other Runge‐Kutta 6(5) pairs as illustrated with various numerical tests in oscillatory problems.