Diode

Hello, I have problem with drive solenoids in circut where have MOSFET tranzistor. Circut is built like this : to source is conect solenoid(one side, and one side is conect to positive polarity of source (12V)) , to drain is conect ground, and to gate control voltage (wich drive betwen 0 and 12 V) . And now, because is to spource(pin on MOSFET) conect solenoid , he have (after is MOSFET closed) own autoinduction ! Becourse this hapend I nead have conect one DIODE near MOSFET, that help MOSFET from courrent which doing aoutoinduction. But, if I conect this diode he phoursing courrent (from solenoid to ground) in every time, becourse is positeve polarity in anode , and negative in catode. How doing this, that this not hapend? Thank you