What is the mental representation of phonetic space? Perceptual reorganization in infancy yields a reconfigured space “warped” around native-language (L1) categories. Is this reconfiguration entirely specific to L1 category inventory? Or does it apply to a broader range of category distinctions that are non-native, yet discriminable due to being defined by phonetic dimensions informative in the listener’s L1 (Bohn & Best, 2012; Pajak, 2012)? Here we address this question by studying perceptual magnets, which involve attrition of within-category distinctions and enhancement of distinctions across category boundaries (Kuhl, 1991). We focus on segmental length, known to yield L1-specific perceptual magnets: e.g., L1-Finnish listeners have one for [t]/[tt], but L1-Dutch listeners, who lack (exclusively) length-based contrasts, do not (Herren & Schouten, 2008). We tested 31 L1-Korean listeners in an AX discrimination task for [n]-[nn] and [f]-[ff] continua. Korean listeners have been shown to discriminate both (Pajak, 2012), despite only having the former set in the inventory. We found perceptual magnets for both continua, demonstrating that perceptual warping goes beyond the specific L1 categories: when a phonetic dimension is informative for contrasting some L1 categories, perceptual warping applies not only to the tokens from those categories, but also to that dimension more generally.