diff --git a/src/pdm/backend/_vendor/packaging/specifiers.py b/src/pdm/backend/_vendor/packaging/specifiers.py
index 2b9feb0..645214a 100644
--- a/src/pdm/backend/_vendor/packaging/specifiers.py
+++ b/src/pdm/backend/_vendor/packaging/specifiers.py
@@ -4,8 +4,8 @@
 """
 .. testsetup::
 
-    from pdm.backend._vendor.packaging.specifiers import Specifier, SpecifierSet, InvalidSpecifier
-    from pdm.backend._vendor.packaging.version import Version
+    from packaging.specifiers import Specifier, SpecifierSet, InvalidSpecifier
+    from packaging.version import Version
 """
 
 import abc
diff --git a/src/pdm/backend/_vendor/packaging/version.py b/src/pdm/backend/_vendor/packaging/version.py
index b9b6184..e5c738c 100644
--- a/src/pdm/backend/_vendor/packaging/version.py
+++ b/src/pdm/backend/_vendor/packaging/version.py
@@ -4,7 +4,7 @@
 """
 .. testsetup::
 
-    from pdm.backend._vendor.packaging.version import parse, Version
+    from packaging.version import parse, Version
 """
 
 import collections
diff --git a/src/pdm/backend/_vendor/pyproject_metadata/__init__.py b/src/pdm/backend/_vendor/pyproject_metadata/__init__.py
index 0f6544b..f61ffad 100644
--- a/src/pdm/backend/_vendor/pyproject_metadata/__init__.py
+++ b/src/pdm/backend/_vendor/pyproject_metadata/__init__.py
@@ -13,10 +13,10 @@ import typing
 from collections.abc import Mapping
 from typing import Any
 
-import pdm.backend._vendor.packaging.markers as pkg_markers
-import pdm.backend._vendor.packaging.requirements as pkg_requirements
-import pdm.backend._vendor.packaging.specifiers as pkg_specifiers
-import pdm.backend._vendor.packaging.version as pkg_version
+import packaging.markers as pkg_markers
+import packaging.requirements as pkg_requirements
+import packaging.specifiers as pkg_specifiers
+import packaging.version as pkg_version
 
 
 __version__ = '0.7.1'
diff --git a/src/pdm/backend/_vendor/tomli_w/__init__.py b/src/pdm/backend/_vendor/tomli_w/__init__.py
index 5324bfa..d7db4cd 100644
--- a/src/pdm/backend/_vendor/tomli_w/__init__.py
+++ b/src/pdm/backend/_vendor/tomli_w/__init__.py
@@ -1,4 +1,4 @@
 __all__ = ("dumps", "dump")
 __version__ = "1.0.0"  # DO NOT EDIT THIS LINE MANUALLY. LET bump2version UTILITY DO IT
 
-from pdm.backend._vendor.tomli_w._writer import dump, dumps
+from tomli_w._writer import dump, dumps
diff --git a/src/pdm/backend/config.py b/src/pdm/backend/config.py
index e71e1ee..48b618a 100644
--- a/src/pdm/backend/config.py
+++ b/src/pdm/backend/config.py
@@ -6,8 +6,8 @@ import sys
 from pathlib import Path
 from typing import Any, TypeVar
 
-from pdm.backend._vendor import tomli_w
-from pdm.backend._vendor.pyproject_metadata import ConfigurationError, StandardMetadata
+import tomli_w
+from pyproject_metadata import ConfigurationError, StandardMetadata
 from pdm.backend.exceptions import ConfigError, ValidationError
 from pdm.backend.structures import Table
 from pdm.backend.utils import find_packages_iter
@@ -15,7 +15,7 @@ from pdm.backend.utils import find_packages_iter
 if sys.version_info >= (3, 11):
     import tomllib
 else:
-    import pdm.backend._vendor.tomli as tomllib
+    import tomli as tomllib
 
 T = TypeVar("T")
 
diff --git a/src/pdm/backend/editable.py b/src/pdm/backend/editable.py
index 0a5ba0c..b637797 100644
--- a/src/pdm/backend/editable.py
+++ b/src/pdm/backend/editable.py
@@ -6,7 +6,7 @@ from pathlib import Path
 
 from editables import EditableProject
 
-from pdm.backend._vendor.packaging.utils import canonicalize_name
+from packaging.utils import canonicalize_name
 from pdm.backend.exceptions import ConfigError, PDMWarning
 from pdm.backend.hooks.base import Context
 from pdm.backend.utils import to_filename
diff --git a/src/pdm/backend/hooks/version/scm.py b/src/pdm/backend/hooks/version/scm.py
index 14a39a9..8c97e70 100644
--- a/src/pdm/backend/hooks/version/scm.py
+++ b/src/pdm/backend/hooks/version/scm.py
@@ -15,7 +15,7 @@ from datetime import datetime
 from pathlib import Path
 from typing import Any, Iterable, NamedTuple
 
-from pdm.backend._vendor.packaging.version import Version
+from packaging.version import Version
 
 DEFAULT_TAG_REGEX = re.compile(
     r"^(?:[\w-]+-)?(?P<version>[vV]?\d+(?:\.\d+){0,2}[^\+]*)(?:\+.*)?$"
diff --git a/src/pdm/backend/intree.py b/src/pdm/backend/intree.py
index 4a77e83..b19a9d7 100644
--- a/src/pdm/backend/intree.py
+++ b/src/pdm/backend/intree.py
@@ -8,7 +8,7 @@ import pdm.backend as api
 if sys.version_info >= (3, 11):
     import tomllib
 else:
-    import pdm.backend._vendor.tomli as tomllib
+    import tomli as tomllib
 
 
 def get_requires_for_build_wheel(
diff --git a/src/pdm/backend/sdist.py b/src/pdm/backend/sdist.py
index c812b29..f13d770 100644
--- a/src/pdm/backend/sdist.py
+++ b/src/pdm/backend/sdist.py
@@ -8,7 +8,7 @@ from pathlib import Path
 from posixpath import join as pjoin
 from typing import Iterable
 
-from pdm.backend._vendor.packaging.utils import canonicalize_name
+from packaging.utils import canonicalize_name
 from pdm.backend.base import Builder
 from pdm.backend.hooks import Context
 from pdm.backend.utils import safe_version, to_filename
diff --git a/src/pdm/backend/utils.py b/src/pdm/backend/utils.py
index 390c6fc..18a6ff1 100644
--- a/src/pdm/backend/utils.py
+++ b/src/pdm/backend/utils.py
@@ -13,10 +13,10 @@ from fnmatch import fnmatchcase
 from pathlib import Path
 from typing import Callable, Generator, Iterable, Match
 
-from pdm.backend._vendor.packaging import tags
-from pdm.backend._vendor.packaging.markers import Marker
-from pdm.backend._vendor.packaging.requirements import Requirement
-from pdm.backend._vendor.packaging.version import InvalidVersion, Version
+from packaging import tags
+from packaging.markers import Marker
+from packaging.requirements import Requirement
+from packaging.version import InvalidVersion, Version
 from pdm.backend.macosx_platform import calculate_macosx_platform_tag
 
 
diff --git a/src/pdm/backend/wheel.py b/src/pdm/backend/wheel.py
index 072757a..dfaa8eb 100644
--- a/src/pdm/backend/wheel.py
+++ b/src/pdm/backend/wheel.py
@@ -14,9 +14,9 @@ from base64 import urlsafe_b64encode
 from pathlib import Path
 from typing import IO, Any, Iterable, Mapping, NamedTuple, cast
 
-from pdm.backend._vendor.packaging import tags
-from pdm.backend._vendor.packaging.specifiers import SpecifierSet
-from pdm.backend._vendor.packaging.utils import canonicalize_name
+from packaging import tags
+from packaging.specifiers import SpecifierSet
+from packaging.utils import canonicalize_name
 from pdm.backend.base import Builder
 from pdm.backend.hooks import Context
 from pdm.backend.hooks.setuptools import SetuptoolsBuildHook