How to modify a load command of a Mach-O binary using LIEF

With LIEF I can read a load command of an iOS Mach-O binary easily, however, I cannot find a way to modify its values. This is an example of what I have tried:

import lief
b=lief.parse("myBinary")
s = [ c  for c in b.commands if c.command.name == "ENCRYPTION_INFO_64"][0]
print(s)
s.crypt_size=1234
b.write("modifiedBinary")

However, s.crypt_size in the modified binary remains unchanged.

Is there a way, or should I post an issue to LIEF?