This chapter discusses the place, if any, of Convention T (the condition of material adequacy of the proper definition of truth formulated by Alfred Tarski) in the truth-makers account offered by Kevin Mulligan, Peter Simons, and Barry Smith. It is argued that although Tarski's requirement seems entirely acceptable in the frameworks of truth-maker theories at first sight, several doubts arise under a closer inspection. In particular, T-biconditionals have no clear meaning as sentences about truth-makers. Thus, the truth-maker theory cannot be considered as the semantic theory of truth enriched by metaphysical (ontological) data. The problem of truth-makers for sentences about future events is discussed at the end of this chapter.