diff --git a/pdfly/cli.py b/pdfly/cli.py
index b258fc3..4559eed 100644
--- a/pdfly/cli.py
+++ b/pdfly/cli.py
@@ -283,7 +283,9 @@ def update_offsets(
             resolve_path=True,
         ),
     ],
-    file_out: Path = typer.Option(..., "-o", "--output"),  # noqa
+    file_out: Annotated[
+        Path, typer.Option("-o", "--output")  # noqa
+    ] = None,  # type: ignore
     encoding: str = typer.Option(
         "ISO-8859-1",
         help="Encoding used to read and write the files, e.g. UTF-8.",
diff --git a/resources/file-with-invalid-offsets.pdf b/resources/file-with-invalid-offsets.pdf
index b2fbc2d..75f7829 100644
Binary files a/resources/file-with-invalid-offsets.pdf and b/resources/file-with-invalid-offsets.pdf differ
diff --git a/tests/test_update_offsets.py b/tests/test_update_offsets.py
index c239577..6246249 100644
--- a/tests/test_update_offsets.py
+++ b/tests/test_update_offsets.py
@@ -14,17 +14,14 @@
 
 def test_update_offsets(capsys, tmp_path: Path) -> None:
     # Arrange
-    input = str(RESOURCES_ROOT / "file-with-invalid-offsets.pdf")
+    input = RESOURCES_ROOT / "file-with-invalid-offsets.pdf"
     file_expected = str(RESOURCES_ROOT / "file-with-fixed-offsets.pdf")
-    output = tmp_path / "file-with-offsets-out.pdf"
-    assert not output.exists()
 
     # Act
     exit_code = run_cli(
         [
             "update-offsets",
             str(input),
-            str(output),
         ]
     )
 
@@ -32,11 +29,10 @@ def test_update_offsets(capsys, tmp_path: Path) -> None:
     captured = capsys.readouterr()
     assert exit_code == 0, captured
     assert not captured.err
-    assert re.search(r"Wrote\s+" + re.escape(str(output)), captured.out)
-    assert output.exists()
+    assert re.search(r"Wrote\s+" + re.escape(str(input)), captured.out)
     with open(file_expected, encoding="iso-8859-1") as file_exp:
         lines_exp = file_exp.readlines()
-    with open(output, encoding="iso-8859-1") as file_act:
+    with input.open(encoding="iso-8859-1") as file_act:
         lines_act = file_act.readlines()
     assert len(lines_exp) == len(
         lines_act
@@ -92,6 +88,7 @@ def test_update_offsets_on_all_reference_files(
             "--encoding",
             "iso-8859-1",
             input_pdf_filepath,
+            "-o",
             str(output_pdf_filepath),
         ]
     )