Two laboratories have reported that children with ASD are less likely than their typical peers to fill pauses with um but their use of uh is unaffected (Irvine et al., J Autism Dev Disord 46(3):1061-1070, 2016; Gorman et al., Autism Res 9(8):854-865, 2016). In this brief report, we replicated this finding by comparing the discourse of 7-to-15-year-olds with ASD (N = 31) to that of their typically developing same-age peers (N = 32). The robustness of this easily documented difference in discourse suggests a potentially useful clinical marker of ASD.