How do I turn off/on the page protection bit?

[Dimpen]

Using CSVDYLPA instead of LOAD GLOBAL=YES modules are loaded into page protected storage. For one of the modules I have the need to store the SSID of our subsystem stc. I rememember from MVS days that I could turn off/on the page protection bit. But I cannot find a service or how to do this now on z/OS. I have not tried PGSER UNPROTECT/PROTECT, but that would just turn off/on the fetch protection bit?