diff --git a/nhf/touhou/houjuu_nue/test.py b/nhf/touhou/houjuu_nue/test.py
index 2eb8cd7..1f6265a 100644
--- a/nhf/touhou/houjuu_nue/test.py
+++ b/nhf/touhou/houjuu_nue/test.py
@@ -7,20 +7,24 @@ class Test(unittest.TestCase):
     def test_hs_joint_parent(self):
         p = M.Parameters()
         obj = p.hs_joint_parent()
-        assert isinstance(obj.val().solids(), Cq.Solid), "H-S joint must be in one piece"
+        self.assertIsInstance(obj.val().solids(), Cq.Solid, msg="H-S joint must be in one piece")
     def test_wing_root(self):
         p = M.Parameters()
         obj = p.wing_root()
-        assert isinstance(obj.solids(), Cq.Solid), "Wing root must be in one piece"
+        self.assertIsInstance(obj.solids(), Cq.Solid, msg="Wing root must be in one piece")
     def test_wings(self):
         p = M.Parameters()
         p.wing_r1()
     def test_harness(self):
         p = M.Parameters()
         p.harness_assembly()
-    def test_trident():
+    def test_trident(self):
         p = M.Parameters()
-        p.trident_assembly()
+        assembly = p.trident_assembly()
+        bbox = assembly.toCompound().BoundingBox()
+        length = bbox.zlen
+        self.assertGreater(length, 1300)
+        self.assertLess(length, 1700)
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/nhf/touhou/houjuu_nue/trident.py b/nhf/touhou/houjuu_nue/trident.py
index e270e74..75e4d73 100644
--- a/nhf/touhou/houjuu_nue/trident.py
+++ b/nhf/touhou/houjuu_nue/trident.py
@@ -26,5 +26,7 @@ def trident_assembly(
         .constrain("i2?lip", "s2?mate1", "Plane", param=0)
         .add(handle.insertion(), name="i3", color=mat_i.color)
         .constrain("s2?mate2", "i3?lip", "Plane", param=0)
+        .add(handle.one_side_connector(), name="head", color=mat_i.color)
+        .constrain("i3?mate", "head?mate", "Plane")
     )
     return assembly.solve()