Previous studies have demonstrated that native listeners modify their interpretation of a speech sound when a talker produces an ambiguous sound in order to quickly tune into a speaker, but there is hardly any evidence that non-native listeners employ a similar mechanism when encountering ambiguous pronunciations. So far, one study demonstrated this lexically-guided perceptual learning effect for nonnatives, using phoneme categories similar in the native language of the listeners and the non-native language of the stimulus materials. The present study investigates the question whether phoneme category retuning is possible in a nonnative language for a contrast, /l/-/r/, which is phonetically differently embedded in the native (Dutch) and nonnative (English) languages involved. Listening experiments indeed showed a lexically-guided perceptual learning effect. Assuming that Dutch listeners have different phoneme categories for the native Dutch and non-native English /r/, as marked differences between the languages exist for /r/, these results, for the first time, seem to suggest that listeners are not only able to retune their native phoneme categories but also their non-native phoneme categories to include ambiguous pronunciations.