The phenomenon of Suffixaufnahme refers to a type of morphosyntactic agreement whereby a dependent noun phrase shows case agreement with its head in addition to its functional case marking. The phenomenon is best known from Old Georgian and Hurro-Urartian, but also occurs elsewhere (Caucasus, ancient Mesopotamia, Australia), mainly in agglutinative languages. Classical Armenian shows a very similar type of agreement: dependents of heads in the accusative marked by the direct object proclitic z= may also receive the same proclitic marking regardless of their functional case. This paper explores two dimensions of this agreement phenomenon in Classical Armenian: a classification of its usage in fifth-century texts; and an attempt at explaining its likely origin outside of Armenian.