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
@@ -5,7 +5,7 @@ from unittest import TestCase
 
 from .. import *
 from .. import gf256
-from ..core import encode, decode,detect_encoding, _share_byte
+from ..core import encode, decode, detect_encoding, _share_byte, compute_x
 
 
 class TestShamira(TestCase):
@@ -29,7 +29,7 @@ class TestShamira(TestCase):
 			_share_byte("x", 2, 3)
 
 		ys = _share_byte(ord(b"a"), 2, 3)
-		xs = list(range(1, 4))
+		xs = compute_x(3)
 
 		weights = gf256.compute_weights(xs)
 		self.assertEqual(gf256.get_constant_coef(weights, ys), ord(b"a"))