Fixed Asset & Profit and Loss question

Please help ? How to rectify P&L mistake from last year? Example, prior year 2017 purchased fixed asset (hire purchase for 3years) but did not capitalise and was treated as rental expense. During the year 2018 fixed assets was recognised and my double entry: 1/1/2018 DR Fixed asset $3600 CR HP Creditor $3600 (to recognise the FA) 1/1/2018 DR HP Creditor $300 (3600/12 = $300/year) CR Rental expenses $300 ? (prior year recognise $300 as rental expense) or CR Accu Depreciation $300 but what about depreciation expenses? Jimmy.