International audience ; Belgium was one of the first European countries to be involved in the modern mathematics movement of the 1960s. The reform was led by a university professor (Georges Papy), supported by a number of enthusiastic teachers of general secondary education. The reformers showed almost no interest in technical education. In the mid-1960s, however, it became clear that also the mathematics programs of technical secondary education would be modernized. We examine the diverse reactions of stakeholders of technical education to the announced reform. Emile Ridiaux and like-minded teachers prepared and attempted to use modern mathematics for technical applications. Others, e.g. inspector Charles-François Becquet, resisted the upcoming reform, but his organization called MATEC, could not stand up to the well-oiled machine of Papy and his disciples. Consequently, from September 1, 1969, modern mathematics was generalized in all technical secondary schools in Belgium.