Tries scored by grounding the ball against the padded post protector will no longer be allowed under a new World Rugby rule change.
World Rugby says the change to Law 8 comes into effect immediately.
A try had previously been awarded if the ball was grounded against the padding of the post.
The rule change was rubber-stamped by the World Rugby Council during a special meeting held via videoconference on Tuesday.
It follows a recommendation by the international federation's Rugby Committee and specialist Laws Review Group.
World Rugby say, "With defending players currently legally obliged to stay behind the goal-line and post-protector shape and size increasing for welfare reasons, it is increasingly difficult for teams to legally defend this area.
"In some extreme cases, post protectors have been lifted or moved by defending teams, leaving the posts exposed and therefore increasing the risk of injury."
The new law now reads: "A try is scored when the attacking player is first to ground the ball in the opponents’ in-goal."
Recently re-elected World Rugby chairman said of the alteration, "World Rugby’s mission is to make the game as simple, safe and enjoyable to play as possible. This law amendment reflects that mission.
"By stipulating that an attacking team can no longer score against the post protector and therefore must ground the ball in-goal, this gives defending teams a fair chance of preventing a try from being scored."
Meanwhile, World Rugby say there has been a positive response to their trials of new rules aimed at improving player welfare.
A number of rule changes have been trialled in French lower division (or community) rugby, including reducing the tackle height to waist-level.
World Rugby say that's resulted "in a three-fold decrease in injuries and a 60 per cent reduction in concussion in the French community game".