Evolution of the cyclotron line energy E_cyc in Her X-1. Shown are the pulse phase averaged E_cyc values normalized to a reference ASM count rate of 6.8 cts s^-1 using a flux dependence of 0.44 keV/ASM−cts s^-1. The red points for 1996–2015 (MJD 50 000–57 300) and the corresponding linear best fit (dashed line) are reproduced from Staubert et al. (2016). The blue points are the new measurements (see Table 1). The flux-normalized values (blue) are NuSTAR 2016: 37.6 ± 0.14 keV, INTEGRAL 2016a: 37.59 ± 0.82 keV, and INTEGRAL 2016b: 38.47 ± 0.71 keV. The 20-year decay of E_cyc has ended with a strong indication of an inversion.