Influenza viruses rely on an RNA-dependent RNA polymerase, sometimes known as FluPol (comprising PB1, PB2 and P3 subunits), that both transcribes and replicates the viral RNA genome. Transcription initiation occurs by cap-snatching and depends on a viral RNA (vRNA) promoter; all currently available FluPol structures reflect this transcription pre-initiation state, with vRNA bound to FluPol. Now, Hengrung et al. report a new FluPol structure without vRNA. This structure reveals a novel 'closed' conformation in which the central PB1 subunit (which houses the polymerase active site) is capped on one end by PB2 and clamped between the two globular domains of P3. Notably, the cap-binding domain of PB2 is occluded in this closed state, suggesting that binding of the vRNA is responsible for substantial conformational changes that induce the transition of FluPol to the 'opened' transcription pre-initiation state.