A safety barrier for a loading dock lift that includes a lift platform that can be raised and lowered. The safety barrier includes a sleeve attached to the lift platform extending along a vertical axis. The sleeve includes guides to define open and closed positions of said gate and said shaft includes a pin that interacts with the guides to produce rotation of said gate between open and closed positions. Consequently each embodiment gate automatically closes due to gravity whenever the lift is raised off the ground and thereby assures that that gates are locked in position when the lift platform has been raised a short distance.