Relative systematic errors of the envelope rotation rates as a function of luminosity for MOLA, SOLA, and eMOLA inversions shown with light red, red, and dark red points, respectively, for the 1 M_⊙ track. The bump luminosity is shown with a vertical dotted grey line. Here, the envelope step profile has been used. Results for the 1.5 and 2 M_⊙ tracks show the same behaviour. In contrast to MOLA and SOLA inversions, the eMOLA results do not suffer from systematic errors.