A printhead is provided for an inkjet printer. The printhead includes an elongate spine defining a channel and first location formations. An elongate ink distribution extrusion is receivable in the channel and defines spaced apart sets of ink supply holes. A printhead module locator defines second location formations which engage with said first location formations. A set of serially arranged ink ejection printhead modules is positioned adjacent the locator, and along the extrusion, so that the printhead modules engage with respective sets of ink supply holes.