Suppressing enabled newer facilities of an older simulated machine. This makes the native machine appear just like the corresponding older simulated machine. The invention creates the Allowed Facilities Table (AFT) that includes all the facilities of each simulated machine that needs to be supported and queries all the installed facilities of the simulated machine. It reads each machine facility of the simulated machine and checks the AFT that includes the state of all the facilities that are allowed to be enabled for the simulated machine to see if this installed facility is also enabled in the AFT. If the installed facility is also enabled in the AFT, then this facility may be used by the software without any problems. Otherwise, this facility should not be used. A system and program product for carrying out the method are included.