Stop Lending Money To People In Naira

The title might seem unpatriotic, but not entirely so.
Quick story
In 2018 I sold an SUV to a friend at 3.5m, he paid 2m and said he would balance up in the future.
Fast forward to 2021 October he pays me ₦1m with a pending balance of ₦500,000.
Vehicle sold in 2018 is now ₦5.3m in 2021.
Lesson learnt.
Going forward all transactions that have to do with pending payments will be signed as dollar equivalents .
Meaning if you want to take a loan or owe me large sums of money E.g ₦1m (sept 2021 2,433.5799 US Dollars) all we will do is check current dollar rate and peg repayment on the dollar equivalent in the future (2,433.5799 US Dollars)