catch up depreciation

My husband and I bought a rental home in July of 2016.  There was a renter in the house which we continued on with until  August of 2017 when they moved out.   We had to do some reno/remodel  (almost $10K) work on the house from September of 2017 until February of 2018 when we rented it out again.   We never added the cost of these improvements to our 2017 or 2018 returns for depreciation.  Can we do this now, for our 2019 return or do we have to file amended returns for those years instead?  

Thank you in advance for your reply!!