Far infrared and sub-millimeter observations of quasars and normal star forming galaxies at z>6 have revealed the presence of large amounts of dust. At such high redshifts, the inferred 107-109 M_ȯ masses of dust must have formed in less than one billion years. Explaining this rapid chemical evolution is a challenge for both observations and theoretical models. Here we discuss the relative role of the two main stellar sources, AGB stars and SNe, in early dust enrichment, in light of new theoretical dust yields for AGB stars.