Controlling an internal combustion engine operated on gaseous fuel

A method for controlling an internal combustion engine (100) during operation on at least partly gaseous fuel is disclosed. The method comprises providing (step 400) a desired burn rate profile (604, 604c) corresponding to a desired operation of the internal combustion engine (100), and first operating parameters that are selected such that an operation of the internal combustion engine (100) with a first gas composition obtains a first burn rate profile that corresponds to the desired burn rate profile (604, 604c). The method further comprises operating (step 404) the internal combustion engine (100) with the first operating parameters on a second gas composition, determining (step 406) that a second burn rate profile (606, 606c) differs from the desired burn rate profile (604, 604c) thereby indicating that the second gas composition differs from the first gas composition, and adapting (steps 408A, 408B) an operating parameter of the first operating parameters of the internal combustion engine (100) to approach the desired burn rate profile (604, 604c).