Evolution of the He Iλ5876 emission profile. Pre-SN spectra show complex P Cygni-like profiles. Soon after the SN occurs, an additional absorption component is seen in the −6d Lick/Kast spectrum at around −5000 km s⁻¹. At late times, the P Cygni absorption is no longer observed, but rather a double-peaked emission profile consisting of host emission and redshifted He I emission at similar velocities as seen in the −93d Keck/LRIS spectrum. Spectra marked with an asterisk have been re-binned for clarity, with the raw spectrum given in grey. We manually masked out telluric lines and artefacts from the sky subtractions.