Superfluid helium droplets He-N at 0.4 K are doped with single alkaline earth atoms (Ca, Sr), The absorption spectra for excitation of the lowest singlet transitions display broad, blue-shifted peaks if compared to the atomic lines. The shift increases with droplet size increasing from N approximate to 1000 up to N approximate to 10000 but converges to only about one third of the bulk value. (C) 1997 American Institute of Physics.