In languages with an underlying consonantal length contrast, the most salient acoustic cue differentiating singletons and geminates is duration of closure. When concatenation of identical phonemes through affixation or compounding produces “fake” geminates, these may or may not be realized phonetically as true geminates. English and German no longer have a productive length contrast in consonants, but do allow sequences of identical consonants in certain morphological contexts, e.g., suffixation (green-ness; zahl-los “countless”) or compounding (pine nut; Schul-leiter “headmaster”). The question is whether such concatenated sequences are produced as geminates and realized acoustically with longer closure duration, and whether this holds in both languages. This issue is investigated here by analyzing the acoustics of native speakers reading suffixed and compound words containing both fake geminate and non-geminate consonants in similar phonological environments. Results indicate that the closure duration is consistently nearly twice as long for fake geminates across conditions. In addition, voice onset time is proportionally longer for fake geminates in English while vowel duration shows few significant differences (in German sonorants only). These results suggest that English and German speakers articulate fake geminates with acoustic characteristics similar to those found in languages with an underlying length contrast, despite no longer displaying the contrast morpheme-internally.