diff --git a/tests/test_cli.py b/tests/test_cli.py
index 447244b..9bef725 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -3,6 +3,7 @@
 from unittest.mock import patch
 
 import numpy as np
+import pytest
 from typer.testing import CliRunner
 
 from bimorph_mirror_analysis import __version__
@@ -11,7 +12,14 @@
 runner = CliRunner()
 
 
-def test_app():
+@pytest.mark.parametrize(
+    ["outpath"],
+    [
+        ["tests/data/out.csv"],
+        [False],
+    ],
+)
+def test_app(outpath: str | bool):
     with (
         patch("bimorph_mirror_analysis.__main__.np.savetxt") as mock_np_save,
         patch(
@@ -19,7 +27,22 @@ def test_app():
         ) as mock_calculate_optimal_voltages,
     ):
         mock_calculate_optimal_voltages.return_value = np.array([72.14, 50.98, 18.59])
-        result = runner.invoke(app, ["calculate-voltages", "tests/data/raw_data.csv"])
+        if outpath is not False:
+            print("\n\n\n\n\n\n")
+            result = runner.invoke(
+                app,
+                [
+                    "calculate-voltages",
+                    "tests/data/raw_data.csv",
+                    "--output_path",
+                    f"{outpath}",
+                ],
+            )
+            print("aaa")
+        elif not outpath:
+            result = runner.invoke(
+                app, ["calculate-voltages", "tests/data/raw_data.csv"]
+            )
         mock_np_save.assert_called_once()
         mock_calculate_optimal_voltages.assert_called_with("tests/data/raw_data.csv")
         assert "The optimal voltages are: [72.14, 50.98, 18.59]" in result.stdout