diff --git a/tools/check_source/check_mypy_config.py b/tools/check_source/check_mypy_config.py
index 2131ca6b757..b7cbc9464b8 100644
--- a/tools/check_source/check_mypy_config.py
+++ b/tools/check_source/check_mypy_config.py
@@ -85,8 +85,6 @@ PATHS_EXCLUDE = set(
         "tools/utils_ide/qtcreator/externaltools/qtc_sort_paths.py",
         "tools/utils_maintenance/blender_menu_search_coverage.py",  # Uses `bpy`.
         "tools/utils_maintenance/blender_update_themes.py",  # Uses `bpy`.
-        "tools/utils_maintenance/trailing_space_clean.py",
-        "tools/utils_maintenance/trailing_space_clean_config.py",
     )
 )
 
diff --git a/tools/utils_maintenance/trailing_space_clean.py b/tools/utils_maintenance/trailing_space_clean.py
index aee63881c71..d6ad3b8b254 100755
--- a/tools/utils_maintenance/trailing_space_clean.py
+++ b/tools/utils_maintenance/trailing_space_clean.py
@@ -12,6 +12,12 @@ from os.path import join
 
 from trailing_space_clean_config import PATHS
 
+from collections.abc import (
+    Callable,
+    Iterator,
+    Sequence,
+)
+
 SOURCE_EXT = (
     # C/C++
     ".c", ".h", ".cpp", ".hpp", ".cc", ".hh", ".cxx", ".hxx", ".inl",
@@ -33,11 +39,14 @@ SOURCE_EXT = (
 )
 
 
-def is_source(filename):
+def is_source(filename: str) -> bool:
     return filename.endswith(SOURCE_EXT)
 
 
-def path_iter(path, filename_check=None):
+def path_iter(
+        path: str,
+        filename_check: Callable[[str], bool] | None = None,
+) -> Iterator[str]:
     for dirpath, dirnames, filenames in os.walk(path):
         # skip ".git"
         dirnames[:] = [d for d in dirnames if not d.startswith(".")]
@@ -50,7 +59,10 @@ def path_iter(path, filename_check=None):
                 yield filepath
 
 
-def path_expand(paths, filename_check=None):
+def path_expand(
+        paths: Sequence[str],
+        filename_check: Callable[[str], bool] | None = None,
+) -> Iterator[str]:
     for f in paths:
         if not os.path.exists(f):
             print("Missing:", f)
@@ -60,17 +72,18 @@ def path_expand(paths, filename_check=None):
             yield f
 
 
-def rstrip_file(filename):
+def rstrip_file(filename: str) -> tuple[str, ...]:
     reports = []
     with open(filename, "r", encoding="utf-8") as fh:
         data_src = fh.read()
 
     # Strip trailing space.
-    data_dst = []
+    data_dst_list = []
     for l in data_src.rstrip().splitlines(True):
-        data_dst.append(l.rstrip() + "\n")
+        data_dst_list.append(l.rstrip() + "\n")
 
-    data_dst = "".join(data_dst)
+    data_dst = "".join(data_dst_list)
+    del data_dst_list
 
     # Remove BOM.
     if data_dst and (data_dst[0] == '\ufeff'):
@@ -86,7 +99,7 @@ def rstrip_file(filename):
     return tuple(reports)
 
 
-def main():
+def main() -> None:
     for f in path_expand(PATHS, is_source):
         report = rstrip_file(f)
         if report:
diff --git a/tools/utils_maintenance/trailing_space_clean_config.py b/tools/utils_maintenance/trailing_space_clean_config.py
index 98114c95153..6b34b497eb1 100644
--- a/tools/utils_maintenance/trailing_space_clean_config.py
+++ b/tools/utils_maintenance/trailing_space_clean_config.py
@@ -9,7 +9,13 @@ __all__ = (
 
 
 import os
-PATHS = (
+from collections.abc import (
+    Callable,
+    Iterator,
+)
+
+
+PATHS: tuple[str, ...] = (
     "build_files/build_environment/cmake",
     "build_files/cmake",
     "doc/python_api",
@@ -38,7 +44,7 @@ PATHS = tuple(
 )
 
 
-def files(path, test_fn):
+def files(path: str, test_fn: Callable[[str], bool]) -> Iterator[str]:
     for dirpath, dirnames, filenames in os.walk(path):
         # skip '.git'
         dirnames[:] = [d for d in dirnames if not d.startswith(".")]