"Wryneck" was put into Reserve during the economic crisis of the 1930s and laid up in Gibraltar. In 1938 she was selected for WAIR conversion to a fast escort ship at Gibraltar Dockyard. The work began in September 1939 and was not completed until March 1940. In April 1940, after sea trials, "Wryneck" was recommissioned for service with the new pennant number L04, and assigned to convoy defence duty based at Alexandria. In December she was detached to support military operations against the Italian army in Egypt.