Certain nonwords, like maluma and takete, are associated with roundness and sharpness, respectively. However, this has typically been demonstrated using explicit tasks. We investigated whether this association would be detectable using a more implicit measure—a sequential priming task. We began with a replication of the standard Maluma/Takete effect (Experiments 1a and 1b) before examining whether round and sharp nonword primes facilitated the categorization of congruent shapes (Experiment 2). We found modest evidence of a priming effect in response accuracy. We next examined whether nonword primes affected categorization of ambiguous shapes, using visual (Experiment 3) and auditory primes (Experiment 4). We found that ambiguous shapes were categorized as round (sharp) more often following the presentation of a round (sharp) nonword. This suggests that phonemes may activate related shape information which then affects the processing of shapes, and that this association emerges even when participants are not explicitly searching for it.