diff --git a/nhf/test.py b/nhf/test.py
index 03015ad..9c215ff 100644
--- a/nhf/test.py
+++ b/nhf/test.py
@@ -1,8 +1,13 @@
 import unittest
+import cadquery as Cq
 import nhf.joints
 
 class TestJoints(unittest.TestCase):
 
+    def test_joint_hirth(self):
+        j = nhf.joints.hirth_joint()
+        assert isinstance(j.val().solids(), Cq.Solid),\
+            "Hirth joint must be in one piece"
     def test_joints_hirth_assembly(self):
         nhf.joints.hirth_assembly()
     def test_joints_comma_assembly(self):
diff --git a/nhf/touhou/houjuu_nue/test.py b/nhf/touhou/houjuu_nue/test.py
index 435d7e8..91808a7 100644
--- a/nhf/touhou/houjuu_nue/test.py
+++ b/nhf/touhou/houjuu_nue/test.py
@@ -1,11 +1,17 @@
 import unittest
+import cadquery as Cq
 import nhf.touhou.houjuu_nue as M
 
 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"
     def test_wing_root(self):
         p = M.Parameters()
-        p.wing_root()
+        obj = p.wing_root()
+        assert isinstance(obj.solids(), Cq.Solid), "Wing root must be in one piece"
     def test_wings(self):
         p = M.Parameters()
         p.wing_r1()