Movement disorders such as Parkinson’s disease (PD) and dystonia are associated with dysfunction of the chaperone protein torsinA. Cao et al. identified FDA-approved small molecules that promote torsinA activity in C. elegans, including ampicillin. Ampicillin improved torsinA activity in human patient cells, and restored motor coordination and balance in a mouse model of early-onset torsion dystonia. Ampicillin derivatives may hold therapeutic potential for patients with movement disorders.