More Dereferencing

code/game/objects/items/devices/sensor_device.dm

@@ -1,5 +1,5 @@
 /obj/item/device/sensor_device
-	name = "handheld crew monitor" 
+	name = "handheld crew monitor"
 	desc = "A miniature machine that tracks suit sensors across the station."
 	icon = 'icons/obj/device.dmi'
 	icon_state = "scanner"
@@ -7,10 +7,15 @@
 	slot_flags = SLOT_BELT
 	origin_tech = "biotech=3;materials=3;magnets=3"
 	var/datum/nano_module/crew_monitor/crew_monitor
-	
+
 /obj/item/device/sensor_device/New()
 	crew_monitor = new(src)
 
+/obj/item/device/sensor_device/Destroy()
+	qdel(crew_monitor)
+	crew_monitor = null
+	return ..()
+
 /obj/item/device/sensor_device/attack_self(mob/user as mob)
 	ui_interact(user)