Update vault files to new solidworks version

I am using Workgroup PDM and there are still some SW2013 files. Now when I open some assembly and make changes to just one part, WPDM wants to make new revision for all parts, because SW saves them as 2014 version and it thinks I have made some changes into them. Is there a way to update all vault files from 2013 to 2014?

SolidworksWorkgroup Pdm