Locking mechanism assemblies are provided for retaining a slide-room of a recreational vehicle in a retracted position. An exemplary assembly has a strut member extending between the slide-room and a wall of the recreational vehicle. The strut member is pivotable between a first position and a second position corresponding to an extended position and a retracted position, respectively, of the slide-room. The assembly further includes a guide member coupled to the strut member and movable therewith such that pivoting motion of the strut member between the first position and the second position causes corresponding linear motion of the guide member along a guide between a first position and a second position. The strut member applies a compressive force to the slide-room and a vehicle wall adjacent the slide-room to inhibit movement of the slide-room when the slide-room is in the retracted position.