On a problem of C. Baak and M.S. Moslehian

In this work, we prove that every Jordan θ -derivation is a θ -derivation. So we give an affirmative answer to a problem posed by C. Baak and M.S. Moslehian in the paper [C. Baak and M.S. Moslehian, On the stability of θ -derivations on J B ∗ -triples, Bull. Braz. Math. Soc. 38 (1) (2007) 115–127].