diff --git a/pyclean/runner.py b/pyclean/runner.py
index 6032579..4cd167e 100644
--- a/pyclean/runner.py
+++ b/pyclean/runner.py
@@ -4,25 +4,36 @@
 
 """Cleanup runner with dry-run and file operations functionality."""
 
+from __future__ import annotations
+
 import logging
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from argparse import Namespace
+    from pathlib import Path
 
 log = logging.getLogger(__name__)
 
 
+def noop(_: Path) -> None:
+    """No-op function for uninitialized runner."""
+
+
 class CleanupRunner:
     """Execution engine with object counting, logging and optional dry-run."""
 
     def __init__(self):
         """Cleanup runner with optional dry-run behavior."""
-        self.unlink = None
-        self.rmdir = None
-        self.ignore = None
-        self.unlink_count = None
-        self.unlink_failed = None
-        self.rmdir_count = None
-        self.rmdir_failed = None
-
-    def configure(self, args):
+        self.unlink = noop
+        self.rmdir = noop
+        self.ignore: list[str] = []
+        self.unlink_count = 0
+        self.unlink_failed = 0
+        self.rmdir_count = 0
+        self.rmdir_failed = 0
+
+    def configure(self, args: Namespace) -> None:
         """Set up runner according to command line options."""
         self.unlink = print_filename if args.dry_run else remove_file
         self.rmdir = print_dirname if args.dry_run else remove_directory
@@ -36,7 +47,7 @@ def configure(self, args):
 Runner = CleanupRunner()
 
 
-def remove_file(fileobj):
+def remove_file(fileobj: Path) -> None:
     """Attempt to delete a file object for real."""
     log.debug('Deleting file: %s', fileobj)
     try:
@@ -47,7 +58,7 @@ def remove_file(fileobj):
         Runner.unlink_failed += 1
 
 
-def remove_directory(dirobj):
+def remove_directory(dirobj: Path) -> None:
     """Attempt to remove a directory object for real."""
     log.debug('Removing directory: %s', dirobj)
     try:
@@ -58,13 +69,13 @@ def remove_directory(dirobj):
         Runner.rmdir_failed += 1
 
 
-def print_filename(fileobj):
+def print_filename(fileobj: Path) -> None:
     """Only display the file name, used with --dry-run."""
     log.debug('Would delete file: %s', fileobj)
     Runner.unlink_count += 1
 
 
-def print_dirname(dirobj):
+def print_dirname(dirobj: Path) -> None:
     """Only display the directory name, used with --dry-run."""
     log.debug('Would delete directory: %s', dirobj)
     Runner.rmdir_count += 1
diff --git a/pyclean/traversal.py b/pyclean/traversal.py
index 2a984f0..ddf967d 100644
--- a/pyclean/traversal.py
+++ b/pyclean/traversal.py
@@ -4,6 +4,8 @@
 
 """Directory traversal and ignore pattern matching."""
 
+from __future__ import annotations
+
 import logging
 import os
 from pathlib import Path
@@ -23,7 +25,7 @@ def normalize(path_pattern: str) -> str:
     return path_pattern.replace(os.sep, os.altsep or os.sep)
 
 
-def should_ignore(pathname: str, ignore_patterns: list[str]) -> bool:
+def should_ignore(pathname: str, ignore_patterns: list[str] | None) -> bool:
     """
     Check if a path should be ignored based on ignore patterns.
 
diff --git a/tests/test_traversal.py b/tests/test_traversal.py
index 2fb6559..117c144 100644
--- a/tests/test_traversal.py
+++ b/tests/test_traversal.py
@@ -92,8 +92,7 @@ def test_should_ignore(path_str, patterns, expected):
     """
     Does should_ignore correctly match path patterns?
     """
-    path = Path(path_str)
-    result = should_ignore(path, patterns)
+    result = should_ignore(path_str, patterns)
     assert result == expected
 
 
@@ -112,8 +111,7 @@ def test_should_ignore_windows_paths(path_str, patterns, expected):
     Does should_ignore correctly handle Windows-style backslash patterns?
     This test only runs on Windows where backslash is a path separator.
     """
-    path = Path(path_str)
-    result = should_ignore(path, patterns)
+    result = should_ignore(path_str, patterns)
     assert result == expected