diff --git a/nhf/touhou/houjuu_nue/joints.py b/nhf/touhou/houjuu_nue/joints.py
index 4e2834a..5700aba 100644
--- a/nhf/touhou/houjuu_nue/joints.py
+++ b/nhf/touhou/houjuu_nue/joints.py
@@ -650,7 +650,7 @@ class ShoulderJoint(Model):
             .copyWorkplane(Cq.Workplane('XY'))
             .box(
                 length=self.child_lip_ext,
-                width=self.child_lip_width,
+                width=self.child_lip_width - 2 * self.child_lip_thickness,
                 height=self.height - self.torsion_joint.total_height * 2,
                 combine='cut',
                 centered=(False, True, True),