In response to the crash investigation, Fokker was forced to improve quality control on the production line, particularly varnishing of the wing spars and ribs, to combat moisture. Fokker also strengthened the rib structures and the attachment of the auxiliary spars to the ribs. Existing triplanes were repaired and modified at Fokker's expense. After testing a modified wing at Adlershof, "Idflieg" authorized the triplane's return to service on 28 November 1917. Production resumed in early December. By January 1918, "Jastas" 6 and 11 were fully equipped with the triplane. Only 14 squadrons used the Dr.I as their primary equipment. Most of these units were part of "Jagdgeschwadern" I, II, or III. Frontline inventory peaked in late April 1918, with 171 aircraft in service on the Western Front.