A thermostat for a transmission oil circuit has a thermostat inlet, a thermostat outlet, and a bypass channel, which fluidically connects the thermostat inlet to the thermostat outlet. A circuit inlet and a circuit outlet are provided for coupling to a cooler. A control element and a pressure loss element are accommodated in the interior of the thermostat housing. The pressure loss element is arranged in the bypass channel, and the control element is arranged between the thermostat inlet and the circuit inlet or the circuit outlet and the thermostat outlet. The thermostat can be connected directly to a housing of the transmission.