However, since the Korean Dynasty was afraid that the information about their defensive preparation along the territory might be leaked to the wako pirates, they limited the entry of koriwasen (ships used to deliver daily necessities such as rice, fish and salt) in 1407, so that these ships were allowed to use only the Pusanpo (port of Busan) and the Seiho (port of Sei, and this port was also called Naijiho), which both were located in Jinhae City, South Gyeongsang Province. The Dynasty also applied the same policy to shisosen (ships used to dispatch envoys) in 1410.
しかし各地の防備の状況が倭寇に漏れるのを恐れ、交易統制のためもあり、1407年、朝鮮王朝は興利倭船（米、魚、塩など日常品の交易をする船）の入港場を釜山浦・薺浦（乃而浦とも、慶尚南道の鎮海市）に制限し、1410年には使送船（使節による通交船）についても同様の措置が取られる。