Various hoisting systems with anti-two-block sensing devices are provided. In one embodiment, an apparatus includes a hoisting system having a hoisting line, a sleeve positioned on the hoisting line, and an anti-two-block sensing device installed about the hoisting line so as to allow the hoisting line to move through the anti-two-block sensing device. The anti-two-block sensing device includes a detector positioned to detect a sleeve component when the sleeve is present within the anti- two-block sensing device. Additional systems, devices, and methods are also disclosed.