A design structure for eliminating step response power supply perturbation during voltage island power-up/power-down on an integrated circuit is disclosed. An IC chip communicates with a primary power supply and includes at least one voltage island. A primary header on the voltage island of the chip communicates with the primary power supply via a primary header power path. A secondary header on the voltage island of the chip communicates with a secondary power supply via a secondary header power path. A control decoder communicating with the IC chip and the voltage island regulates the state of the primary and secondary headers.