ILR coming up, but family would have 2 fewer months than 5 years

[asthanaiitk]

Hello,
I would be due to apply for my ILR in April next year, as my 5yrs Tier2 visa runs out. My family joined me 2 months after my arrival to UK. They applied for their visas later, and their visa would lapse along with mine. This would leave them 2 months short of 5 years stay at the time my ILR is due. What are my options regarding their visas? Do I need a short extension for them (if it is possible)?
Thanks a lot in advance for your help!
Ashish