diff --git a/tests/test_invocation.py b/tests/test_invocation.py
index 0c100011..41c3e3ed 100644
--- a/tests/test_invocation.py
+++ b/tests/test_invocation.py
@@ -39,7 +39,7 @@ def test_run_wrapper(program):
 
 def test_conversion_xls():
     proc = subprocess.run(
-        ('gnpy-convert-xls', SRC_ROOT / 'tests' / 'data' / 'testTopology.xls', '--output', '/dev/null'),
+        ('gnpy-convert-xls', SRC_ROOT / 'tests' / 'data' / 'testTopology.xls', '--output', os.path.devnull),
         stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True, universal_newlines=True)
     assert proc.stderr == ''
-    assert '/dev/null' in proc.stdout
+    assert os.path.devnull in proc.stdout