A safety device for an aerial lift (10) having a basket (20) with controls (23) which permit an operator to manoeuvre the basket (20), and a foot operable safety switch (24) which activates the controls (23), the safety device comprising an auxiliary safety switch (24) operated by a trip cord (27) arranged proximate to the controls (23) and which is connected in series with the foot safety switch (24) so that in the event that the cord is distorted the auxiliary switch (26) prevents activation of the control panel (23) and may additionally operate an alarm.