diff --git a/.coverage b/.coverage
index ade5727..fde3bfd 100644
Binary files a/.coverage and b/.coverage differ
diff --git a/Makefile b/Makefile
index 9beb8a4..2b74d48 100644
--- a/Makefile
+++ b/Makefile
@@ -34,3 +34,6 @@ update:
 docker:
 	docker build --no-cache -f Dockerfile -t change_me-smoke .
 	docker run --rm change_me-smoke
+
+app:
+	poetry run python -m change_me
diff --git a/README.md b/README.md
index 8eb8aee..55ae526 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ To install the library run: `pip install change-me`
 5. `poetry publish --build` to build and publish to https://pypi.org/project/change-me
 
 
-## Usage
+## Module Usage
 ```
 """Basic docstring for my module."""
 
@@ -26,3 +26,8 @@ logger.info("Hello World!")
 if __name__ == "__main__":
     main()
 ```
+
+## Program Usage
+```bash
+poetry run python -m change_me
+```
diff --git a/src/change_me/__main__.py b/src/change_me/__main__.py
index 1304e39..2161425 100644
--- a/src/change_me/__main__.py
+++ b/src/change_me/__main__.py
@@ -8,19 +8,19 @@
 from change_me.utils import setup_logger
 
 
-def main(log_level: str) -> None:
+def main(log_level: str = DEFAULT_LOG_LEVEL) -> None:
     """Run the pipeline."""
     setup_logger(filename="log_file", log_dir=None, log_level=log_level)
-    logger.info("Hello world!")
+    logger.info("Hello, world!")
 
 
-if __name__ == "__main__":
-    parser = argparse.ArgumentParser()
+if __name__ == "__main__":  # pragma: no cover
+    parser = argparse.ArgumentParser("Run the pipeline.")
     parser.add_argument(
         "--log-level",
         default=DEFAULT_LOG_LEVEL,
-        choices=list(LogLevel),
-        help="Log level.",
+        choices=list(LogLevel()),
+        help="Set the log level.",
     )
     args = parser.parse_args()
 
diff --git a/tests/main_test.py b/tests/main_test.py
new file mode 100644
index 0000000..add1078
--- /dev/null
+++ b/tests/main_test.py
@@ -0,0 +1,10 @@
+"""Test the main program."""
+
+from change_me.__main__ import main
+
+
+def test_main():
+    """Test the main function."""
+    result = main()
+
+    assert result is None
diff --git a/tests/utils_test.py b/tests/utils_test.py
index e5ddf72..8da207f 100644
--- a/tests/utils_test.py
+++ b/tests/utils_test.py
@@ -3,13 +3,23 @@
 from pathlib import Path
 from tempfile import TemporaryDirectory
 
+from change_me.definitions import LogLevel
 from change_me.utils import setup_logger
 
 
-def test_logger_init():
+def test_logger_init() -> None:
     """Test logger initialization."""
     with TemporaryDirectory() as log_dir:
         log_dir_path = Path(log_dir)
         log_filepath = setup_logger(filename="log_file", log_dir=log_dir_path)
         assert Path(log_filepath).exists()
     assert not Path(log_filepath).exists()
+
+
+def test_log_level() -> None:
+    """Test the log level."""
+    # Act
+    log_levels = list(LogLevel())
+
+    # Assert
+    assert type(log_levels) is list