A connector is provided with a housing (10) including a lock arm (25) configured to hold a mating housing (90) in a connected state and a detector (60) to be assembled movably to a standby position and a detection position with respect to the housing (10). The lock arm (25) includes pressure receiving portions (33). The detector (60) includes pressing portions (69) configured to displace the lock arm (25) in a direction to increase a locking margin with a lock portion by pressing the pressure receiving portions (33) at least either when the detector (60) reaches the detection position or when an external force acts on the detector (60) in a direction opposite to a direction toward the standby position.