In a resounding victory for electronics reuse advocates in the U.S., the Librarian of Congress has granted individuals and companies alike the right to unlock used phones and tablets for the next three years.

The ruling eliminates a key obstacle for companies attempting to re-market used devices and concludes more than a year of uncertainty surrounding the future legality of unlocking in the U.S.

The Librarian of Congress, newly seated David S. Mao, concluded the arguments presented by unlocking proponents, particularly iFixit, the Electronic Frontier Foundation the Institute of Scrap Recycling Industries, were convincing.

“They explained that the inability to unlock one’s wireless devices leads to adverse effects by impeding consumers’ ability to choose their preferred wireless carriers, harming the resale value of used devices, and harming the environment by encouraging disposal rather than reuse of devices,” Mao wrote in his decision.

The aspect of the ruling that has to do with device unlocking, which can be read here, is effective immediately and will hold for three years. In it, Mao weighs in on a number of exemptions related to the Digital Millennium Act (DMCA) of 1998.

The DMCA tasks the librarian every three years with determining whether individual and bulk unlocking of cellphones, tablets and other mobile devices is prohibited under copyright law. After a surprise decision in 2012 deemed unlocking illegal, proponents helped urge Congress to pass the Unlocking Act in 2014, which temporarily overturned the ban.

While the phone industry had fought vehemently in the past to outlaw unlocking, just one company – TracFone – filed comments in opposition to the cellphone unlocking exemption this time around. No tablet manufacturer filed opposition.

“The heavy, coordinated criticism from both the public and repair/digital rights organizations seems to have made a mark,” iFixit CEO Kyle Wiens wrote in a wrap-up on the decision.