Later the merging project advanced only between the Universities of Paris 4 and Paris 6 but was forced to reconsider the name Sorbonne Université. The compromise in 2010 consisted of adding a "s" at the end of the name of the project (the future merged University would be named later), making it Sorbonne Universités. In 2018 the project effectively merged the former universities of Paris 4 and 6, taking the name "Sorbonne-Université" with or without the hyphen. In line with the naming convention and with the former crisis of 2006 in the background, the number in the name disappears and the accompanying name becomes "Sorbonne Université", replacing "Paris-Sorbonne" and "Pierre et Marie Curie".