This paper examines the morphological interaction of possessor agreement and the number of the possessor and possessed noun in Turkish and Sakha, two distantly related Turkic languages. Of particular focus are third-person posses- sors, where both languages can use the regular nominal plural suffix -LAr to index 3PL possessors, and (similar to many Turkic languages) do not allow two instances of -LAr in sequence, resulting in a three-way ambiguity, e.g. Sakha at-tar-ï [horse-PL-3.POSS] a. ‘his/her horses,’ b. ‘their horse,’ c. ‘their horses.’ In Turkish, this ambiguity obtains only with pro-dropped possessors, as an overt plural possessor does not index plurality on singular nouns, whereas in Sakha 3PL agreement is obligatory. It is argued that in Sakha, 3PL possession is true agreement, whereas in Turkish the pattern that obtains under pro-drop is a result of the possessor’s PL feature lowering onto the possessed noun. Further, we examine the nature of the *-lar-lar haplology (i.e. the fact that a 3PL-possessing-PL cannot be marked with -lar twice: e.g. Sakha *at-tar-dar-a [horse-PL-PL-3P] ‘their horses,’ contending that it is a particular property of the exponent -lar which occurs during Vocabulary-Insertion.