A screening assembly 10 includes at least one rail 14 to be secured to a support member of a screening machine to lie parallel to, and intermediate, side members of the screening machine. At least one locating formation 18 stands proud of an operatively upper surface of each rail 14. The assembly includes a plurality of screening modules 12. Each screening module 12 has an end supported on the rail 14 so that a pair of modules 12 lie in end-to-end abutting relationship with the abutting ends, in use, overlying the rail 12 and defining a receiving formation through which the locating formation 18 protrudes to project beyond the receiving formation into a recessed region defined by the abutting ends of the pair of modules 12. A locking member 46 is associated with the receiving formation and is receivable in the recessed region for engaging its associated locating formation to lock the pair of modules with respect to each other and with respect to the rail 14. An upper surface of the locking member 46, when the locking member is received in the recessed region, lies substantially flush with upper surfaces of the modules 12 of the pair of modules.