The querela inofficiosi testamenti (action for undutiful will) did not permit the joinder of parties. When there were several forced heirs, each heir brought the action independently with the intention of obtaining the distributive share that would have been due according to intestate succession. Each plaintiff normally acted only for his own share. Whether the plaintiff could benefit from an inheritance increase if it was known that one or more co-heirs had repudiated their claim is unclear. The passages from the Digest seem to give conflicting answers and modern scholars suspect that there might have been ius controversum on the subject. Based on two Byzantine scholia, the author demonstrates that the jurists’ diverging conclusions referred to different cases. In the end, the exegesis of the texts offers some reflections about the work of the Justinianic Compilers.