A new Call of Duty game means that everyone hopping into the multiplayer mode starts at square one, slowly earning experience points as they climb the ranks and unlock new gear. For some players, Call of Duty: Modern Warfare II‘s XP grind isn’t quick enough, and they’ve taken it upon themselves to speed up the process.

As discovered by a user on Reddit, the process is simple. All you need is a suppression mine and enough courage to face an enemy tank with an open top, and once you’ve located that vehicle, you can jump onto it and place your mine behind the turret. Find a safe place to hide, and watch the XP flow in as players inside of the tank are constantly hit by the mine. Repeat as necessary and you’ll soon work your way up multiple ranks in multiplayer.

This is of course not how Activision intended for players to earn XP, and by the time you read this, the exploit could have been singled out for a quick hotfix. Infinity Ward has been quick on the trigger to squash any bugs, and the latest patch has already targeted a number of exploits. That update has fixed “various map exploits” and has addressed an issue that previously stopped players from being able to edit their Profile Showcase.

Since it launched, Call of Duty: Modern Warfare II has had a high number of bugs that players have documented, such as one exploit that allowed for enemies to be shot through walls. Infinity Ward is keeping track of any issues in the game’s multiplayer mode with a public Trello board, with visual glitches and hard crashes on the current list.

Those minor issues haven’t stopped Modern Warfare II from being a huge hit this year, as the game earned $800 million worldwide in just three days and has had the biggest PlayStation store launch of all time for the COD series. To see how this year’s entry shapes up, you can read GameSpot’s Modern Warfare II campaign and Modern Warfare II multiplayer reviews.