An inkjet printhead includes: an elongate fluid manifold having at least one longitudinally extending channel, the fluid manifold having a base defining a plurality of fluid outlets, the fluid outlets being spaced apart along a floor of the channel; a plurality of printhead chips bonded to the base of the fluid manifold, each printhead chip receiving ink from one or more fluid outlets; and a plurality of transverse ribs positioned across the channel, each transverse rib extending upwardly from the floor of the channel.