Verify standby supervisor engine ios-xe image fails

[LuensmannIT]

Hi, there,

I've a couple of WS-C4507R+E switches (Version 03.08.07.E.152-4.E7) with installed standby supervisor engine.

Verifying the ios-xe image on the primary supervisor engine works, but verifying and image on the slavebootflash doesn't work:

HOSTNAME#verify bootflash:/cat4500es8-universalk9.SPA.03.08.07.E.152-4.E7.bin
Digital signature successfully verified in package cat4500es8-base.SPA.03.08.07.E.pkg
Digital signature successfully verified in package cat4500es8-firmware.SPA.03.08.07.E.pkg
Digital signature successfully verified in package cat4500es8-infra.SPA.03.08.07.E.pkg
Digital signature successfully verified in package cat4500es8-universalk9.SPA.152-4.E7.pkg
Digital signature successfully verified in file bootflash:/cat4500es8-universalk9.SPA.03.08.07.E.152-4.E7.bin

HOSTNAME#verify slavebootflash:/cat4500es8-universalk9.SPA.03.08.07.E.152-4.E7.bin
Error Verifying file slavebootflash:/cat4500es8-universalk9.SPA.03.08.07.E.152-4.E7.bin

Is this a expected behavior?
Do i have to attach (attach module 4", "session module 4") to the standby supervisor engine first and execute the verify command from the standby supervisor engine itself?