While allomorphy is a widespread phenomenon in the functional vocabulary of the world’s languages (i.e. English past tense <i>-d, -t</i> and <i>-Ø</i>), its status in the domain of roots is still an open question. Does root allomorphy, or suppletion, exist? In this paper we review the recent controversy attached to this question within the framework of Distributed Morphology (DM) and then provide an argument in favor of the existence of suppletion from the distribution of vocabulary items <i>mat-</i> (kill) and <i>mor-</i> (die). Using a model for analyzing suppletion outlined in Harley (2013), we propose that these two vocabulary items are members of the same set of lists that are accessed by a single syntactically-active root node. <i>Mat-</i> is specified to appear in agentive verbal environments while <i>mor</i>- is an elsewhere morpheme.