Abstract: A foldable sofa sleeper mechanism having pivotally interconnected head, body, intermediate, and foot sections movable between a folded position in which the mechanism is contained within a storage enclosure of a sofa frame, and an extended unfolded position in which the bed frame extends in a planar attitude away from the sofa frame, and tilt prevention means for preventing the head end of the unfolded sofa sleeper mechanism from tilting downwardly when an excessive weight is placed thereon, which tilt prevention means includes at least one anti-tilt link and at least one anti-tilt lever, wherein one end of the link is connected to the mechanism at one location and the other end of the link is connected to one end of the lever, with the lever being pivotally connected to the mechanism at another location.