The short-lived change meant blocked users could still view and interact with tweets from the person who blocked them, and could not see they had been blocked.
Twitter said this was to protect victims of harassment who feared blocking a user would lead to retaliation.
But after a wave of online protest Twitter re-instated its previous policy whereby blocked users are notified, and cannot follow or interact with the blocker.
Michael Sippey of Twitter said: "We have decided to revert the change after receiving feedback from many users - we never want to introduce features at the cost of users feeling less safe."
Several online petitions were launched and Twitter users rallied behind the hashtag #restoretheblock to complain about the change.
One user tweeted : "Dear @Twitter, you protect abusers. You've let my stalkers invade my life and regain control."