diff --git a/pip_manage/__init__.py b/pip_manage/__init__.py
index d8720a2b..e05d690c 100644
--- a/pip_manage/__init__.py
+++ b/pip_manage/__init__.py
@@ -3,6 +3,6 @@
 from __future__ import annotations
 
 __version__: Final[str] = "1.0.3"
-__title__: Final[str] = "pip-manage"
+__title__: Literal["pip-manage"] = "pip-manage"
 
-from typing import Final
+from typing import Final, Literal
diff --git a/pip_manage/_logging.py b/pip_manage/_logging.py
index 8ce34b4a..8ed23af9 100644
--- a/pip_manage/_logging.py
+++ b/pip_manage/_logging.py
@@ -36,7 +36,11 @@ def format(self, record: logging.LogRecord) -> str:
         return super().format(record)
 
 
-def setup_logging(logger_name: str, *, verbose: bool) -> None:
+def setup_logging(
+    logger_name: Literal["pip-review", "pip-purge"],
+    *,
+    verbose: bool,
+) -> None:
     level: Literal["DEBUG", "INFO"] = "DEBUG" if verbose else "INFO"
     logging.config.dictConfig(
         {
diff --git a/pip_manage/pip_purge.py b/pip_manage/pip_purge.py
index 3d08f0ea..e837dca2 100755
--- a/pip_manage/pip_purge.py
+++ b/pip_manage/pip_purge.py
@@ -2,13 +2,13 @@
 """pip-purge lets you smoothly uninstall packages and their dependencies."""
 from __future__ import annotations
 
-__title__: Final[str] = "pip-purge"
+__title__: Literal["pip-purge"] = "pip-purge"
 
 import argparse
 import importlib.metadata
 import logging
 from pathlib import Path
-from typing import TYPE_CHECKING, Final, NamedTuple
+from typing import TYPE_CHECKING, Final, Literal, NamedTuple
 
 from pip_manage._logging import setup_logging
 from pip_manage._pip_interface import (
diff --git a/pip_manage/pip_review.py b/pip_manage/pip_review.py
index 10d04759..83c0e0e6 100755
--- a/pip_manage/pip_review.py
+++ b/pip_manage/pip_review.py
@@ -2,13 +2,13 @@
 """pip-review lets you smoothly manage all available PyPI updates."""
 from __future__ import annotations
 
-__title__: Final[str] = "pip-review"
+__title__: Literal["pip-review"] = "pip-review"
 
 import argparse
 import logging
 import os
 from pathlib import Path
-from typing import TYPE_CHECKING, Final, NamedTuple
+from typing import TYPE_CHECKING, Final, Literal, NamedTuple
 
 from pip_manage._logging import setup_logging
 from pip_manage._pip_interface import (