Use 6gbps SAS as Hotspare for RAID5 with 12gbps SAS?

Hi,

we have some old R520 Servers with several 6gbps SAS drives which got replaced by new R540 servers.

Instead of letting the R520 rot i got in mind to use the HDDs as Hot Spares on our new systems..

Our new System is equipped with 12gbps SAS drives..

Is it possible to use the 6gbps SAS drives as hotspares for the 12gbps drives or is this a problem?

Regards