The present invention is concerned with 2-aminoquinoline derivatives of formula I wherein Z, R1, and Ar1 are as defined herein, pharmaceutical compositions containing them, methods for their manufacture. The compounds are 5-HT5A receptor antagonists and are useful in the prevention and/or treatment of depression, anxiety disorders, schizophrenia, panic disorders, agoraphobia, social phobia, obsessive compulsive disorders, post-traumatic stress disorders, pain, memory disorders, dementia, disorders of eating behaviors, sexual dysfunction, sleep disorders, abuse of drugs, motor disorders such as Parkinson's disease, psychiatric disorders or gastrointestinal disorders.