diff --git a/testUpdateHostsFile.py b/testUpdateHostsFile.py
index 62616dbc9..8a3b4e49d 100644
--- a/testUpdateHostsFile.py
+++ b/testUpdateHostsFile.py
@@ -1324,7 +1324,7 @@ class TestFlushDnsCache(BaseStdout):
                 self.assertIn(expected, output)
 
     @mock.patch("os.path.isfile", side_effect=[True, False, False, True] + [False] * 10)
-    @mock.patch("subprocess.call", side_effect=[1, 0])
+    @mock.patch("subprocess.call", side_effect=[1, 0, 0])
     def test_flush_posix_fail_then_succeed(self, *_):
         with self.mock_property("platform.system") as obj:
             obj.return_value = "Linux"