 On 15 May 1916 Watts Morgan transferred to a Works Battalion of the King's Liverpool Regiment, he was promoted to major on 24 November 1916, and went to serve in France. The Works Battalions were absorbed by the Labour Corps (forerunner of the Royal Pioneer Corps) in 1917. Watts Morgan was three times Mentioned in Despatches, and on 4 May 1918 was awarded the Distinguished Service Order for leading his pioneer unit in a counter-attack against German forces that were breaking through British lines. The citation for this award was published on 5 July 1918 and read:
