diff --git a/tests/test_nco.py b/tests/test_nco.py
index 39900b418..719764d02 100644
--- a/tests/test_nco.py
+++ b/tests/test_nco.py
@@ -1,6 +1,7 @@
-import sdr
 import numpy as np
 
+import sdr
+
 
 def test_constant_increment():
     K0 = 1
@@ -14,7 +15,7 @@ def test_constant_increment():
 
     N = 100
     y = nco.step(N)
-    y_truth = np.arange(1, N+1) * increment + offset
+    y_truth = np.arange(1, N + 1) * increment + offset
     assert np.allclose(y, y_truth)
 
 
@@ -30,5 +31,5 @@ def test_constant_increment_constant_offset():
 
     N = 100
     y = nco.step(N)
-    y_truth = np.arange(1, N+1) * increment + offset
+    y_truth = np.arange(1, N + 1) * increment + offset
     assert np.allclose(y, y_truth)