diff --git a/scripts/addons_core/bl_pkg/__init__.py b/scripts/addons_core/bl_pkg/__init__.py
index 827bc69e201..9fc4317fcc6 100644
--- a/scripts/addons_core/bl_pkg/__init__.py
+++ b/scripts/addons_core/bl_pkg/__init__.py
@@ -39,14 +39,12 @@ def _local_module_reload():
     import importlib
     from . import (
         bl_extension_cli,
-        bl_extension_local,
         bl_extension_notify,
         bl_extension_ops,
         bl_extension_ui,
         bl_extension_utils,
     )
     importlib.reload(bl_extension_cli)
-    importlib.reload(bl_extension_local)
     importlib.reload(bl_extension_notify)
     importlib.reload(bl_extension_ops)
     importlib.reload(bl_extension_ui)
diff --git a/scripts/addons_core/bl_pkg/bl_extension_local.py b/scripts/addons_core/bl_pkg/bl_extension_local.py
deleted file mode 100644
index 75fed97bc63..00000000000
--- a/scripts/addons_core/bl_pkg/bl_extension_local.py
+++ /dev/null
@@ -1,46 +0,0 @@
-# SPDX-FileCopyrightText: 2023 Blender Foundation
-#
-# SPDX-License-Identifier: GPL-2.0-or-later
-
-"""
-High level API for managing an extension local site-packages and wheels.
-
-NOTE: this is a standalone module.
-"""
-
-__all__ = (
-    "sync",
-)
-
-
-import os
-import sys
-
-from typing import (
-    List,
-)
-
-from .wheel_manager import WheelSource
-
-
-def sync(
-        *,
-        local_dir: str,
-        wheel_list: List[WheelSource],
-) -> None:
-    from . import wheel_manager
-    local_dir_site_packages = os.path.join(
-        local_dir,
-        "lib",
-        "python{:d}.{:d}".format(sys.version_info.major, sys.version_info.minor),
-        "site-packages",
-    )
-
-    wheel_manager.apply_action(
-        local_dir=local_dir,
-        local_dir_site_packages=local_dir_site_packages,
-        wheel_list=wheel_list,
-    )
-    if os.path.exists(local_dir_site_packages):
-        if local_dir_site_packages not in sys.path:
-            sys.path.append(local_dir_site_packages)
diff --git a/scripts/addons_core/bl_pkg/bl_extension_ops.py b/scripts/addons_core/bl_pkg/bl_extension_ops.py
index ba5487a9c3e..d5c5565dc23 100644
--- a/scripts/addons_core/bl_pkg/bl_extension_ops.py
+++ b/scripts/addons_core/bl_pkg/bl_extension_ops.py
@@ -824,7 +824,7 @@ def _extensions_repo_sync_wheels(repo_cache_store):
     This function collects all wheels from all packages and ensures the packages are either extracted or removed
     when they are no longer used.
     """
-    from .bl_extension_local import sync
+    import addon_utils
 
     repos_all = extension_repos_read()
 
@@ -864,7 +864,8 @@ def _extensions_repo_sync_wheels(repo_cache_store):
     extensions = bpy.utils.user_resource('EXTENSIONS')
     local_dir = os.path.join(extensions, ".local")
 
-    sync(
+    # WARNING: bad level call, avoid making this a public function just now.
+    addon_utils._extension_sync_wheels(
         local_dir=local_dir,
         wheel_list=wheel_list,
     )
diff --git a/scripts/addons_core/bl_pkg/wheel_manager.py b/scripts/modules/_bpy_internal/extensions/wheel_manager.py
similarity index 100%
rename from scripts/addons_core/bl_pkg/wheel_manager.py
rename to scripts/modules/_bpy_internal/extensions/wheel_manager.py
diff --git a/scripts/modules/addon_utils.py b/scripts/modules/addon_utils.py
index 860538e50d4..c064ab6f71a 100644
--- a/scripts/modules/addon_utils.py
+++ b/scripts/modules/addon_utils.py
@@ -765,6 +765,32 @@ def _fake_module_from_extension(mod_name, mod_path):
     return mod
 
 
+def _extension_sync_wheels(
+        *,
+        local_dir,  # `str`
+        wheel_list,  # `List[WheelSource]`
+):  # `-> None`
+    import os
+    import sys
+    from _bpy_internal.extensions.wheel_manager import apply_action
+
+    local_dir_site_packages = os.path.join(
+        local_dir,
+        "lib",
+        "python{:d}.{:d}".format(*sys.version_info[0:2]),
+        "site-packages",
+    )
+
+    apply_action(
+        local_dir=local_dir,
+        local_dir_site_packages=local_dir_site_packages,
+        wheel_list=wheel_list,
+    )
+    if os.path.exists(local_dir_site_packages):
+        if local_dir_site_packages not in sys.path:
+            sys.path.append(local_dir_site_packages)
+
+
 # -----------------------------------------------------------------------------
 # Extensions
 
diff --git a/tools/check_source/check_mypy_config.py b/tools/check_source/check_mypy_config.py
index 4c6a74f8ac6..4fb311f66e3 100644
--- a/tools/check_source/check_mypy_config.py
+++ b/tools/check_source/check_mypy_config.py
@@ -14,6 +14,9 @@ PATHS: Tuple[Tuple[str, Tuple[Any, ...], Dict[str, str]], ...] = (
     ("build_files/utils/", (), {'MYPYPATH': "modules"}),
     ("doc/manpage/blender.1.py", (), {}),
     ("release/datafiles/", (), {}),
+    ("scripts/modules/_bpy_internal/extensions/junction_module.py", (), {}),
+    ("scripts/modules/_bpy_internal/extensions/wheel_manager.py", (), {}),
+    ("scripts/modules/_bpy_internal/freedesktop.py", (), {}),
     ("tools/check_blender_release/", (), {}),
     ("tools/check_docs/", (), {}),
     ("tools/check_source/", (), {'MYPYPATH': "modules"}),