Owners of a gas stove know this little problem. Sure enough, really without tipping, the espresso maker never stands on the flame after all, because it's either too big - or too small. And both involve a certain risk of falling (for the pot, anyway).
Remedy comes in the form of this reducing ring, which is made of cast iron for a good reason. So then it doesn't bother it much if you put it directly on the gas flame, it can withstand that. And since the reducer ring comes from Italy, it is even specialized to serve as a solid base for your espresso maker.