A connector includes a housing and a connector position assurance device (CPA). The CPA is movable between a first position and a second position and assures that the connector is completely mated with a mating connector or maintains a completely mated state in the second position. The housing has a mating portion, a guiding portion, and an abutting portion. The CPA has a base portion guided by the guiding portion and a beam portion. The abutting portion abuts on the beam portion in the first position during non-mating with the mating connector to block movement of the CPA to the second position. The mating connector during complete mating deforms the beam portion to remove the abutment of the beam portion on the abutting portion to allow the CPA to move to the second position.