How to upgrade old hinges with new dampers

We have several older IKEA cabinets with door hinges that are not compatible with the new dampers for kitchen cabinet doors. And we found a way to upgrade old hinges with new dampers:


These hinges have a round hole at the back whereas the new hinges have a rectangular hole for the damper to snap in:


After buying some dampers and some new hinges I figured out the easiest solution to install the dampers to the old hinges would be simply filing the hole into a more rectangular shape:


This worked like a charm! Now almost all of our doors are damped and close smoothly.

Note: for doors with more than 2 hinges more than one damper is needed.