Abstract: The invention relates to a device for filtering of oil circulating in an internal combustion engine, comprising an oil filter adapter for detachable fastening of an exchangeable oil filter to the engine block of the internal combustion engine. The invention is characterized in that the oil filter adapter has a receptacle with an inserted pin, the receptacle having an outflow for returning the oil flowing from the exchangeable oil filter, the receptacle having a channel which leads in particular to an oil pump, and the receptacle having a drain which leads in particular to the cylinder crankcase, the pin being inserted elastically pretensioned such that during operation the pin clears the outflow and closes the channel and the drain, and, when the exchangeable oil filter is loosened from the oil filter adapter, the pin is displaced by spring force and clears the outflow, the channel, and the drain. Furthermore the invention includes a pin which is designed for use in the device according to the invention.