diff --git a/src/shamira/tests/test_shamira.py b/src/shamira/tests/test_shamira.py
--- a/src/shamira/tests/test_shamira.py
+++ b/src/shamira/tests/test_shamira.py
@@ -28,11 +28,17 @@ class TestShamira(TestCase):
 		with self.assertRaises(ValueError):  # not castable to int
 			_share_byte("x", 2, 3)
 
-		vals = _share_byte(ord(b"a"), 2, 3)
-		points = list(zip(range(1, 256), vals))
-		self.assertEqual(gf256.get_constant_coef(*points), ord(b"a"))
-		self.assertEqual(gf256.get_constant_coef(*points[:2]), ord(b"a"))
-		self.assertNotEqual(gf256.get_constant_coef(*points[:1]), ord(b"a"))  # underdetermined => random
+		ys = _share_byte(ord(b"a"), 2, 3)
+		xs = list(range(1, 4))
+
+		weights = gf256.compute_weights(xs)
+		self.assertEqual(gf256.get_constant_coef(weights, ys), ord(b"a"))
+
+		weights = gf256.compute_weights(xs[:2])
+		self.assertEqual(gf256.get_constant_coef(weights, ys[:2]), ord(b"a"))
+
+		weights = gf256.compute_weights(xs[:1])
+		self.assertNotEqual(gf256.get_constant_coef(weights, ys[:1]), ord(b"a"))  # underdetermined => random
 
 	def test_generate_reconstruct_raw(self):
 		for (k, n) in [(2, 3), (254, 254)]: