It is a truism of diachronic linguistic theory that most historically transparent forms are explainable as compromises between sound shifts (the norm) and a wide range of analogical adjustments (the deviation from the norm). In practice, however, scholars have so far made only modest advances in their attempts at analyzing associative interferences with predictable linguistic change. Specifically, if numerous examples have been collected, often at random, of the extension or complete generalization of an inflectional or derivational morph (say, the marker of a number, a gender, or an agent), little has been ascertained, at least in the Romance domain, on the opposite phenomenon, the preservation of a close-knit paradigmatic pattern at the heavy cost of a break in the consistency of a sound correspondence. Though Sapir, and possibly others before him, eloquently outlined the problem of morphological resistance to a sound shift (Language 196–204, ed. 1921), the precise exemplification and even the technique of analysis remain to be provided on the Romance side—a side credited with controlling a particularly suitable portion of experimental data. The present article is meant to mark just one step, long overdue, in this direction.