<p>Previous research has shown that users of certain languages tend to choose and order their words such that they avoid stress clashes. This tendency has been attributed to the Principle of Rhythmic Alternation (PRA). It has also been claimed that language users alternate between morphological structures to abide by the PRA. However, in our estimation, it has not yet been convincingly shown that PRA effects documented for morphology are indeed morphological instead of syntactic or lexical in nature. The present research shows that the alternation between two plural suffixes for certain Dutch nouns is a genuine case of morphological PRA by controlling for alternative mechanisms. We conducted two experiments and one corpus study. In the first experiment, we had participants pluralize nouns which were embedded in sentences such that only one of the plural variants would not lead to stress clash. We did not find a PRA effect in this study—possibly because participants inserted prosodic breaks between the plural and the next word. This explanation was supported by the results of a second follow-up experiment. In the corpus study, we looked at the distribution of plural suffixes for both variable and invariable nouns. As stress clashing plural forms were avoided only for the variable nouns, we can be reasonably confident that this PRA effect was due to a morphological process. Apart from identifying a new PRA phenomenon, this result strengthens previous claims about the relevance of the PRA for models of morphological processing.</p>