diff --git a/src/test/py/test_trigonometry.py b/src/test/py/test_trigonometry.py
index e38fb9f..790be61 100644
--- a/src/test/py/test_trigonometry.py
+++ b/src/test/py/test_trigonometry.py
@@ -52,6 +52,12 @@ class MyTestCase(unittest.TestCase):
             delta *= -1
         self.assertLess(delta, 0.01)
 
+    def test_56_point_7_deg_to_rad_should_be_point99(self):
+        delta = deg2rad(56.7) - 0.99
+        if delta < 0:
+            delta *= -1
+        self.assertLess(delta, 0.01)
+
     def test_sin_0_should_be_0(self):
         self.assertEqual(sin_approx_bhaskara(0), 0)