Using non-words in psycholinguistic research allows for a high level of control over experimental stimuli. However, this relies on the assumption that they reflect natural language. Eliciting acceptability judgements from L1 speakers of the target language is one approach to ensuring the relative authenticity of stimuli. For tonal languages, it is as yet unclear whether tone interacts with the perceived acceptability of non-words. In this between-participant Mandarin non-word norming study, 72 L1 Mandarin listeners judged 750 syllables across five tones: tones 1-4 and the neutral tone (NT). Syllables were analysed as systematic gaps, which do not appear in the lexicon because they violate phonotactic constraints, and accidental gaps, which are phonotactically sound but are absent from the lexicon. Real words and malformed syllables acted as maximally and minimally acceptable controls, respectively. Linear mixed effects models indicate that tones 1-4 do not modulate acceptability judgements. NT had a significant negative effect, but this likely arises from exposure to excised neutral tone syllables out of context rather than ungrammaticality. We suggest that Mandarin non-words can be associated with any lexical tone without concern for its effect on acceptability but that neutral tone stimuli should be presented in context to preserve authenticity.