In February 1918, "London" moved to Rosyth and began conversion to a minelayer. The conversion included removal of all four of her 12-inch (305-mm) guns and her anti-torpedo nets, replacement of her after main-battery turret with a 6-inch gun, and installation of minelaying equipment on her quarterdeck, including rails for 240 mines, and of a canvas screen to conceal the entire quarterdeck from external view. She also received an experimental dazzle camouflage paint scheme. The conversion was completed in April 1918, and on 18 May 1918 "London" recommissioned at Rosyth for service in the Grand Fleet's 1st Minelaying Squadron. Before the war ended on 11 November 1918, "London" had laid 2,640 mines in the Northern Mine Barrage.