restoring backup: Error incompatible ios

Hi,

two months ago my iPhone 6 128gb was stolen and I downgraded to an iPhone 5s 32gb. Because of the difference in size I obviously haven't been able to restore my back up to the new (older) phone.

I've now got an iPhone 6s with sufficient space. However, in the meantime there have been iOS updates meaning that my back-up is still on version 10 whilst the phone that I'm trying to restore onto is already on iOS 11.

Thus when trying to restore from my back up I receive the error message that the back up is incompatible.

Is there anyway I can resolve this?