Celtic have failed to score for their second pre-season friendly in a row after they were beaten 1-0 by German third division side Stuttgart Kickers.
The only goal of the game came two minutes before half time as Omar Jatta headed in Fabio Leutenecker's cross.
Paddy McCourt, Scott Brown, Gary Hooper and Charlie Mulgrew all started for the SPL champions.
Neil Lennon's side drew the opening game of their German tour 0-0 with Ausburg in midweek.