diff --git a/Makefile b/Makefile
index a522fcd..bc273ee 100644
--- a/Makefile
+++ b/Makefile
@@ -12,5 +12,8 @@ test:
 
 .PHONY: cli
 cli: 
-	pipenv run python app/main.py
+	pipenv run python -m app.main
 
+.PHONY: help
+help: 
+	pipenv run python -m app.main --help
diff --git a/README.md b/README.md
index fef1018..5125298 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 ## Stories
 
 - [x] As a user I want to generate a random secure password to protect my personal accounts
-    - [ ] Minimal length
+    - [x] Minimal length
     - [ ] Include symbols
     - [ ] Include numbers
     - [ ] Include lowercase characters
diff --git a/app/main.py b/app/main.py
index 74cc6cc..7d5627d 100644
--- a/app/main.py
+++ b/app/main.py
@@ -6,8 +6,10 @@ app = typer.Typer()
 
 
 @app.command()
-def main() -> None:
-    typer.echo(generate_password(0))
+def main(
+    length: int = typer.Option(8, help="Length of the generated password."),
+) -> None:
+    typer.echo(generate_password(0, length))
 
 
 if __name__ == "__main__":
diff --git a/app/main_test.py b/app/main_test.py
index 2ca6e54..1feb3bf 100644
--- a/app/main_test.py
+++ b/app/main_test.py
@@ -1,10 +1,22 @@
-from typer.testing import CliRunner
+from typer.testing import CliRunner, Result
+
 from .main import app
 
 runner = CliRunner()
 
 
 def test_cli_print_password() -> None:
-    result = runner.invoke(app)
-    assert result.exit_code == 0
+    result = _run_cli()
     assert "2yW4AcqG" in result.stdout
+
+
+def test_cli_can_set_password_length() -> None:
+    args = ["--length", 10]
+    result = _run_cli(*args)
+    assert "2yW4AcqGFz" in result.stdout
+
+
+def _run_cli(*args) -> Result:
+    result = runner.invoke(app, args)
+    assert result.exit_code == 0
+    return result