diff --git a/.flake8 b/.flake8
index 3cf342f93..2f9e6ed27 100644
--- a/.flake8
+++ b/.flake8
@@ -20,7 +20,7 @@ ignore = E265,E266,E731,E704,
          W293, W504,
          ANN0 ANN1 ANN2,
          TC002,
-         # TC0, TC1, TC2
+         TC0, TC1, TC2
          # B,
          A,
          D,
diff --git a/git/config.py b/git/config.py
index 345cb40e6..c4b26ba63 100644
--- a/git/config.py
+++ b/git/config.py
@@ -6,6 +6,7 @@
 """Module containing module parser implementation able to properly read and write
 configuration files"""
 
+import sys
 import abc
 from functools import wraps
 import inspect
@@ -14,12 +15,10 @@
 import os
 import re
 import fnmatch
-from collections import OrderedDict
 
 from git.compat import (
     defenc,
     force_text,
-    with_metaclass,
     is_win,
 )
 
@@ -31,15 +30,24 @@
 
 # typing-------------------------------------------------------
 
-from typing import (Any, Callable, IO, List, Dict, Sequence,
-                    TYPE_CHECKING, Tuple, Union, cast, overload)
+from typing import (Any, Callable, Generic, IO, List, Dict, Sequence,
+                    TYPE_CHECKING, Tuple, TypeVar, Union, cast, overload)
 
-from git.types import Lit_config_levels, ConfigLevels_Tup, PathLike, TBD, assert_never, is_config_level
+from git.types import Lit_config_levels, ConfigLevels_Tup, PathLike, TBD, assert_never, _T
 
 if TYPE_CHECKING:
     from git.repo.base import Repo
     from io import BytesIO
 
+T_ConfigParser = TypeVar('T_ConfigParser', bound='GitConfigParser')
+
+if sys.version_info[:2] < (3, 7):
+    from collections import OrderedDict
+    OrderedDict_OMD = OrderedDict
+else:
+    from typing import OrderedDict
+    OrderedDict_OMD = OrderedDict[str, List[_T]]
+
 # -------------------------------------------------------------
 
 __all__ = ('GitConfigParser', 'SectionConstraint')
@@ -61,7 +69,6 @@
 
 
 class MetaParserBuilder(abc.ABCMeta):
-
     """Utlity class wrapping base-class methods into decorators that assure read-only properties"""
     def __new__(cls, name: str, bases: TBD, clsdict: Dict[str, Any]) -> TBD:
         """
@@ -115,7 +122,7 @@ def flush_changes(self, *args: Any, **kwargs: Any) -> Any:
     return flush_changes
 
 
-class SectionConstraint(object):
+class SectionConstraint(Generic[T_ConfigParser]):
 
     """Constrains a ConfigParser to only option commands which are constrained to
     always use the section we have been initialized with.
@@ -128,7 +135,7 @@ class SectionConstraint(object):
     _valid_attrs_ = ("get_value", "set_value", "get", "set", "getint", "getfloat", "getboolean", "has_option",
                      "remove_section", "remove_option", "options")
 
-    def __init__(self, config: 'GitConfigParser', section: str) -> None:
+    def __init__(self, config: T_ConfigParser, section: str) -> None:
         self._config = config
         self._section_name = section
 
@@ -149,7 +156,7 @@ def _call_config(self, method: str, *args: Any, **kwargs: Any) -> Any:
         return getattr(self._config, method)(self._section_name, *args, **kwargs)
 
     @property
-    def config(self) -> 'GitConfigParser':
+    def config(self) -> T_ConfigParser:
         """return: Configparser instance we constrain"""
         return self._config
 
@@ -157,7 +164,7 @@ def release(self) -> None:
         """Equivalent to GitConfigParser.release(), which is called on our underlying parser instance"""
         return self._config.release()
 
-    def __enter__(self) -> 'SectionConstraint':
+    def __enter__(self) -> 'SectionConstraint[T_ConfigParser]':
         self._config.__enter__()
         return self
 
@@ -165,10 +172,10 @@ def __exit__(self, exception_type: str, exception_value: str, traceback: str) ->
         self._config.__exit__(exception_type, exception_value, traceback)
 
 
-class _OMD(OrderedDict):
+class _OMD(OrderedDict_OMD):
     """Ordered multi-dict."""
 
-    def __setitem__(self, key: str, value: Any) -> None:
+    def __setitem__(self, key: str, value: _T) -> None:  # type: ignore[override]
         super(_OMD, self).__setitem__(key, [value])
 
     def add(self, key: str, value: Any) -> None:
@@ -177,7 +184,7 @@ def add(self, key: str, value: Any) -> None:
             return None
         super(_OMD, self).__getitem__(key).append(value)
 
-    def setall(self, key: str, values: Any) -> None:
+    def setall(self, key: str, values: List[_T]) -> None:
         super(_OMD, self).__setitem__(key, values)
 
     def __getitem__(self, key: str) -> Any:
@@ -194,25 +201,17 @@ def setlast(self, key: str, value: Any) -> None:
         prior = super(_OMD, self).__getitem__(key)
         prior[-1] = value
 
-    @overload
-    def get(self, key: str, default: None = ...) -> None:
-        ...
-
-    @overload
-    def get(self, key: str, default: Any = ...) -> Any:
-        ...
-
-    def get(self, key: str, default: Union[Any, None] = None) -> Union[Any, None]:
-        return super(_OMD, self).get(key, [default])[-1]
+    def get(self, key: str, default: Union[_T, None] = None) -> Union[_T, None]:  # type: ignore
+        return super(_OMD, self).get(key, [default])[-1]          # type: ignore
 
-    def getall(self, key: str) -> Any:
+    def getall(self, key: str) -> List[_T]:
         return super(_OMD, self).__getitem__(key)
 
-    def items(self) -> List[Tuple[str, Any]]:  # type: ignore[override]
+    def items(self) -> List[Tuple[str, _T]]:  # type: ignore[override]
         """List of (key, last value for key)."""
         return [(k, self[k]) for k in self]
 
-    def items_all(self) -> List[Tuple[str, List[Any]]]:
+    def items_all(self) -> List[Tuple[str, List[_T]]]:
         """List of (key, list of values for key)."""
         return [(k, self.getall(k)) for k in self]
 
@@ -238,7 +237,7 @@ def get_config_path(config_level: Lit_config_levels) -> str:
         assert_never(config_level, ValueError(f"Invalid configuration level: {config_level!r}"))
 
 
-class GitConfigParser(with_metaclass(MetaParserBuilder, cp.RawConfigParser)):  # type: ignore ## mypy does not understand dynamic class creation # noqa: E501
+class GitConfigParser(cp.RawConfigParser, metaclass=MetaParserBuilder):
 
     """Implements specifics required to read git style configuration files.
 
@@ -298,7 +297,10 @@ def __init__(self, file_or_files: Union[None, PathLike, 'BytesIO', Sequence[Unio
         :param repo: Reference to repository to use if [includeIf] sections are found in configuration files.
 
         """
-        cp.RawConfigParser.__init__(self, dict_type=_OMD)
+        cp.RawConfigParser.__init__(self, dict_type=_OMD)  # type: ignore[arg-type]
+        self._dict: Callable[..., _OMD]  # type: ignore[assignment]   # mypy/typeshed bug
+        self._defaults: _OMD              # type: ignore[assignment]  # mypy/typeshed bug
+        self._sections: _OMD              # type: ignore[assignment]  # mypy/typeshed bug
 
         # Used in python 3, needs to stay in sync with sections for underlying implementation to work
         if not hasattr(self, '_proxies'):
@@ -309,9 +311,9 @@ def __init__(self, file_or_files: Union[None, PathLike, 'BytesIO', Sequence[Unio
         else:
             if config_level is None:
                 if read_only:
-                    self._file_or_files = [get_config_path(f)
+                    self._file_or_files = [get_config_path(cast(Lit_config_levels, f))
                                            for f in CONFIG_LEVELS
-                                           if is_config_level(f) and f != 'repository']
+                                           if f != 'repository']
                 else:
                     raise ValueError("No configuration level or configuration files specified")
             else:
@@ -424,7 +426,7 @@ def string_decode(v: str) -> str:
             # is it a section header?
             mo = self.SECTCRE.match(line.strip())
             if not is_multi_line and mo:
-                sectname = mo.group('header').strip()
+                sectname: str = mo.group('header').strip()
                 if sectname in self._sections:
                     cursect = self._sections[sectname]
                 elif sectname == cp.DEFAULTSECT:
@@ -535,7 +537,7 @@ def _included_paths(self) -> List[Tuple[str, str]]:
 
         return paths
 
-    def read(self) -> None:
+    def read(self) -> None:  # type: ignore[override]
         """Reads the data stored in the files we have been initialized with. It will
         ignore files that cannot be read, possibly leaving an empty configuration
 
@@ -623,10 +625,11 @@ def write_section(name, section_dict):
 
         if self._defaults:
             write_section(cp.DEFAULTSECT, self._defaults)
+        value: TBD
         for name, value in self._sections.items():
             write_section(name, value)
 
-    def items(self, section_name: str) -> List[Tuple[str, str]]:
+    def items(self, section_name: str) -> List[Tuple[str, str]]:    # type: ignore[override]
         """:return: list((option, value), ...) pairs of all items in the given section"""
         return [(k, v) for k, v in super(GitConfigParser, self).items(section_name) if k != '__name__']
 
diff --git a/git/diff.py b/git/diff.py
index 98a5cfd97..74ca0b64d 100644
--- a/git/diff.py
+++ b/git/diff.py
@@ -15,8 +15,8 @@
 
 # typing ------------------------------------------------------------------
 
-from typing import Any, Iterator, List, Match, Optional, Tuple, Type, TypeVar, Union, TYPE_CHECKING
-from git.types import PathLike, TBD, Literal, TypeGuard
+from typing import Any, Iterator, List, Match, Optional, Tuple, Type, TypeVar, Union, TYPE_CHECKING, cast
+from git.types import PathLike, TBD, Literal
 
 if TYPE_CHECKING:
     from .objects.tree import Tree
@@ -28,9 +28,9 @@
 Lit_change_type = Literal['A', 'D', 'C', 'M', 'R', 'T', 'U']
 
 
-def is_change_type(inp: str) -> TypeGuard[Lit_change_type]:
-    # return True
-    return inp in ['A', 'D', 'C', 'M', 'R', 'T', 'U']
+# def is_change_type(inp: str) -> TypeGuard[Lit_change_type]:
+#     # return True
+#     return inp in ['A', 'D', 'C', 'M', 'R', 'T', 'U']
 
 # ------------------------------------------------------------------------
 
@@ -517,8 +517,8 @@ def _handle_diff_line(lines_bytes: bytes, repo: 'Repo', index: DiffIndex) -> Non
             # Change type can be R100
             # R: status letter
             # 100: score (in case of copy and rename)
-            assert is_change_type(_change_type[0]), f"Unexpected value for change_type received: {_change_type[0]}"
-            change_type: Lit_change_type = _change_type[0]
+            # assert is_change_type(_change_type[0]), f"Unexpected value for change_type received: {_change_type[0]}"
+            change_type: Lit_change_type = cast(Lit_change_type, _change_type[0])
             score_str = ''.join(_change_type[1:])
             score = int(score_str) if score_str.isdigit() else None
             path = path.strip()
diff --git a/git/index/fun.py b/git/index/fun.py
index e071e15cf..49e3f2c52 100644
--- a/git/index/fun.py
+++ b/git/index/fun.py
@@ -53,10 +53,11 @@
 
 from typing import (Dict, IO, List, Sequence, TYPE_CHECKING, Tuple, Type, Union, cast)
 
-from git.types import PathLike, TypeGuard
+from git.types import PathLike
 
 if TYPE_CHECKING:
     from .base import IndexFile
+    from git.db import GitCmdObjectDB
     from git.objects.tree import TreeCacheTup
     # from git.objects.fun import EntryTupOrNone
 
@@ -149,15 +150,15 @@ def write_cache(entries: Sequence[Union[BaseIndexEntry, 'IndexEntry']], stream:
     # body
     for entry in entries:
         beginoffset = tell()
-        write(entry[4])         # ctime
-        write(entry[5])         # mtime
-        path_str: str = entry[3]
+        write(entry.ctime_bytes)         # ctime
+        write(entry.mtime_bytes)         # mtime
+        path_str = str(entry.path)
         path: bytes = force_bytes(path_str, encoding=defenc)
         plen = len(path) & CE_NAMEMASK      # path length
-        assert plen == len(path), "Path %s too long to fit into index" % entry[3]
-        flags = plen | (entry[2] & CE_NAMEMASK_INV)     # clear possible previous values
-        write(pack(">LLLLLL20sH", entry[6], entry[7], entry[0],
-                   entry[8], entry[9], entry[10], entry[1], flags))
+        assert plen == len(path), "Path %s too long to fit into index" % entry.path
+        flags = plen | (entry.flags & CE_NAMEMASK_INV)     # clear possible previous values
+        write(pack(">LLLLLL20sH", entry.dev, entry.inode, entry.mode,
+                   entry.uid, entry.gid, entry.size, entry.binsha, flags))
         write(path)
         real_size = ((tell() - beginoffset + 8) & ~7)
         write(b"\0" * ((beginoffset + real_size) - tell()))
@@ -188,15 +189,16 @@ def entry_key(*entry: Union[BaseIndexEntry, PathLike, int]) -> Tuple[PathLike, i
     """:return: Key suitable to be used for the index.entries dictionary
     :param entry: One instance of type BaseIndexEntry or the path and the stage"""
 
-    def is_entry_key_tup(entry_key: Tuple) -> TypeGuard[Tuple[PathLike, int]]:
-        return isinstance(entry_key, tuple) and len(entry_key) == 2
+    # def is_entry_key_tup(entry_key: Tuple) -> TypeGuard[Tuple[PathLike, int]]:
+    #     return isinstance(entry_key, tuple) and len(entry_key) == 2
 
     if len(entry) == 1:
         entry_first = entry[0]
         assert isinstance(entry_first, BaseIndexEntry)
         return (entry_first.path, entry_first.stage)
     else:
-        assert is_entry_key_tup(entry)
+        # assert is_entry_key_tup(entry)
+        entry = cast(Tuple[PathLike, int], entry)
         return entry
     # END handle entry
 
@@ -244,7 +246,7 @@ def read_cache(stream: IO[bytes]) -> Tuple[int, Dict[Tuple[PathLike, int], 'Inde
     content_sha = extension_data[-20:]
 
     # truncate the sha in the end as we will dynamically create it anyway
-    extension_data = extension_data[:-20]
+    extension_data = extension_data[: -20]
 
     return (version, entries, extension_data, content_sha)
 
@@ -310,7 +312,7 @@ def _tree_entry_to_baseindexentry(tree_entry: 'TreeCacheTup', stage: int) -> Bas
     return BaseIndexEntry((tree_entry[1], tree_entry[0], stage << CE_STAGESHIFT, tree_entry[2]))
 
 
-def aggressive_tree_merge(odb, tree_shas: Sequence[bytes]) -> List[BaseIndexEntry]:
+def aggressive_tree_merge(odb: 'GitCmdObjectDB', tree_shas: Sequence[bytes]) -> List[BaseIndexEntry]:
     """
     :return: list of BaseIndexEntries representing the aggressive merge of the given
         trees. All valid entries are on stage 0, whereas the conflicting ones are left
diff --git a/git/index/typ.py b/git/index/typ.py
index bb1a03845..46f1b0779 100644
--- a/git/index/typ.py
+++ b/git/index/typ.py
@@ -11,7 +11,7 @@
 
 # typing ----------------------------------------------------------------------
 
-from typing import (List, Sequence, TYPE_CHECKING, Tuple, cast)
+from typing import (NamedTuple, Sequence, TYPE_CHECKING, Tuple, Union, cast)
 
 from git.types import PathLike
 
@@ -59,14 +59,37 @@ def __call__(self, stage_blob: Blob) -> bool:
         return False
 
 
-class BaseIndexEntry(tuple):
+class BaseIndexEntryHelper(NamedTuple):
+    """Typed namedtuple to provide named attribute access for BaseIndexEntry.
+    Needed to allow overriding __new__ in child class to preserve backwards compat."""
+    mode: int
+    binsha: bytes
+    flags: int
+    path: PathLike
+    ctime_bytes: bytes = pack(">LL", 0, 0)
+    mtime_bytes: bytes = pack(">LL", 0, 0)
+    dev: int = 0
+    inode: int = 0
+    uid: int = 0
+    gid: int = 0
+    size: int = 0
+
+
+class BaseIndexEntry(BaseIndexEntryHelper):
 
     """Small Brother of an index entry which can be created to describe changes
     done to the index in which case plenty of additional information is not required.
 
     As the first 4 data members match exactly to the IndexEntry type, methods
     expecting a BaseIndexEntry can also handle full IndexEntries even if they
-    use numeric indices for performance reasons. """
+    use numeric indices for performance reasons.
+    """
+
+    def __new__(cls, inp_tuple: Union[Tuple[int, bytes, int, PathLike],
+                                      Tuple[int, bytes, int, PathLike, bytes, bytes, int, int, int, int, int]]
+                ) -> 'BaseIndexEntry':
+        """Override __new__ to allow construction from a tuple for backwards compatibility """
+        return super().__new__(cls, *inp_tuple)
 
     def __str__(self) -> str:
         return "%o %s %i\t%s" % (self.mode, self.hexsha, self.stage, self.path)
@@ -74,20 +97,10 @@ def __str__(self) -> str:
     def __repr__(self) -> str:
         return "(%o, %s, %i, %s)" % (self.mode, self.hexsha, self.stage, self.path)
 
-    @property
-    def mode(self) -> int:
-        """ File Mode, compatible to stat module constants """
-        return self[0]
-
-    @property
-    def binsha(self) -> bytes:
-        """binary sha of the blob """
-        return self[1]
-
     @property
     def hexsha(self) -> str:
         """hex version of our sha"""
-        return b2a_hex(self[1]).decode('ascii')
+        return b2a_hex(self.binsha).decode('ascii')
 
     @property
     def stage(self) -> int:
@@ -100,17 +113,7 @@ def stage(self) -> int:
 
         :note: For more information, see http://www.kernel.org/pub/software/scm/git/docs/git-read-tree.html
         """
-        return (self[2] & CE_STAGEMASK) >> CE_STAGESHIFT
-
-    @property
-    def path(self) -> str:
-        """:return: our path relative to the repository working tree root"""
-        return self[3]
-
-    @property
-    def flags(self) -> List[str]:
-        """:return: flags stored with this entry"""
-        return self[2]
+        return (self.flags & CE_STAGEMASK) >> CE_STAGESHIFT
 
     @classmethod
     def from_blob(cls, blob: Blob, stage: int = 0) -> 'BaseIndexEntry':
@@ -136,40 +139,15 @@ def ctime(self) -> Tuple[int, int]:
         :return:
             Tuple(int_time_seconds_since_epoch, int_nano_seconds) of the
             file's creation time"""
-        return cast(Tuple[int, int], unpack(">LL", self[4]))
+        return cast(Tuple[int, int], unpack(">LL", self.ctime_bytes))
 
     @property
     def mtime(self) -> Tuple[int, int]:
         """See ctime property, but returns modification time """
-        return cast(Tuple[int, int], unpack(">LL", self[5]))
-
-    @property
-    def dev(self) -> int:
-        """ Device ID """
-        return self[6]
-
-    @property
-    def inode(self) -> int:
-        """ Inode ID """
-        return self[7]
-
-    @property
-    def uid(self) -> int:
-        """ User ID """
-        return self[8]
-
-    @property
-    def gid(self) -> int:
-        """ Group ID """
-        return self[9]
-
-    @property
-    def size(self) -> int:
-        """:return: Uncompressed size of the blob """
-        return self[10]
+        return cast(Tuple[int, int], unpack(">LL", self.mtime_bytes))
 
     @classmethod
-    def from_base(cls, base):
+    def from_base(cls, base: 'BaseIndexEntry') -> 'IndexEntry':
         """
         :return:
             Minimal entry as created from the given BaseIndexEntry instance.
diff --git a/git/objects/commit.py b/git/objects/commit.py
index 11cf52a5e..884f65228 100644
--- a/git/objects/commit.py
+++ b/git/objects/commit.py
@@ -39,9 +39,9 @@
 
 # typing ------------------------------------------------------------------
 
-from typing import Any, IO, Iterator, List, Sequence, Tuple, Union, TYPE_CHECKING
+from typing import Any, IO, Iterator, List, Sequence, Tuple, Union, TYPE_CHECKING, cast
 
-from git.types import PathLike, TypeGuard, Literal
+from git.types import PathLike, Literal
 
 if TYPE_CHECKING:
     from git.repo import Repo
@@ -323,16 +323,18 @@ def _iter_from_process_or_stream(cls, repo: 'Repo', proc_or_stream: Union[Popen,
         :param proc: git-rev-list process instance - one sha per line
         :return: iterator returning Commit objects"""
 
-        def is_proc(inp) -> TypeGuard[Popen]:
-            return hasattr(proc_or_stream, 'wait') and not hasattr(proc_or_stream, 'readline')
+        # def is_proc(inp) -> TypeGuard[Popen]:
+        #     return hasattr(proc_or_stream, 'wait') and not hasattr(proc_or_stream, 'readline')
 
-        def is_stream(inp) -> TypeGuard[IO]:
-            return hasattr(proc_or_stream, 'readline')
+        # def is_stream(inp) -> TypeGuard[IO]:
+        #     return hasattr(proc_or_stream, 'readline')
 
-        if is_proc(proc_or_stream):
+        if hasattr(proc_or_stream, 'wait'):
+            proc_or_stream = cast(Popen, proc_or_stream)
             if proc_or_stream.stdout is not None:
                 stream = proc_or_stream.stdout
-        elif is_stream(proc_or_stream):
+        elif hasattr(proc_or_stream, 'readline'):
+            proc_or_stream = cast(IO, proc_or_stream)
             stream = proc_or_stream
 
         readline = stream.readline
@@ -351,7 +353,8 @@ def is_stream(inp) -> TypeGuard[IO]:
         # END for each line in stream
         # TODO: Review this - it seems process handling got a bit out of control
         # due to many developers trying to fix the open file handles issue
-        if is_proc(proc_or_stream):
+        if hasattr(proc_or_stream, 'wait'):
+            proc_or_stream = cast(Popen, proc_or_stream)
             finalize_process(proc_or_stream)
 
     @ classmethod
diff --git a/git/objects/submodule/base.py b/git/objects/submodule/base.py
index d5ba118f6..29212167c 100644
--- a/git/objects/submodule/base.py
+++ b/git/objects/submodule/base.py
@@ -965,13 +965,12 @@ def remove(self, module: bool = True, force: bool = False,
 
             # now git config - need the config intact, otherwise we can't query
             # information anymore
-            writer: Union[GitConfigParser, SectionConstraint]
 
-            with self.repo.config_writer() as writer:
-                writer.remove_section(sm_section(self.name))
+            with self.repo.config_writer() as gcp_writer:
+                gcp_writer.remove_section(sm_section(self.name))
 
-            with self.config_writer() as writer:
-                writer.remove_section()
+            with self.config_writer() as sc_writer:
+                sc_writer.remove_section()
         # END delete configuration
 
         return self
@@ -1024,7 +1023,8 @@ def set_parent_commit(self, commit: Union[Commit_ish, None], check: bool = True)
         return self
 
     @unbare_repo
-    def config_writer(self, index: Union['IndexFile', None] = None, write: bool = True) -> SectionConstraint:
+    def config_writer(self, index: Union['IndexFile', None] = None, write: bool = True
+                      ) -> SectionConstraint['SubmoduleConfigParser']:
         """:return: a config writer instance allowing you to read and write the data
             belonging to this submodule into the .gitmodules file.
 
@@ -1201,7 +1201,7 @@ def name(self) -> str:
         """
         return self._name
 
-    def config_reader(self) -> SectionConstraint:
+    def config_reader(self) -> SectionConstraint[SubmoduleConfigParser]:
         """
         :return: ConfigReader instance which allows you to qurey the configuration values
             of this submodule, as provided by the .gitmodules file
diff --git a/git/objects/submodule/util.py b/git/objects/submodule/util.py
index a776af889..cc1cd60a2 100644
--- a/git/objects/submodule/util.py
+++ b/git/objects/submodule/util.py
@@ -100,7 +100,7 @@ def flush_to_index(self) -> None:
     #} END interface
 
     #{ Overridden Methods
-    def write(self) -> None:
+    def write(self) -> None:  # type: ignore[override]
         rval: None = super(SubmoduleConfigParser, self).write()
         self.flush_to_index()
         return rval
diff --git a/git/objects/tree.py b/git/objects/tree.py
index dd1fe7832..70f36af5d 100644
--- a/git/objects/tree.py
+++ b/git/objects/tree.py
@@ -24,7 +24,7 @@
 from typing import (Any, Callable, Dict, Iterable, Iterator, List,
                     Tuple, Type, Union, cast, TYPE_CHECKING)
 
-from git.types import PathLike, TypeGuard, Literal
+from git.types import PathLike, Literal
 
 if TYPE_CHECKING:
     from git.repo import Repo
@@ -36,8 +36,8 @@
                          Tuple['Submodule', 'Submodule']]]
 
 
-def is_tree_cache(inp: Tuple[bytes, int, str]) -> TypeGuard[TreeCacheTup]:
-    return isinstance(inp[0], bytes) and isinstance(inp[1], int) and isinstance([inp], str)
+# def is_tree_cache(inp: Tuple[bytes, int, str]) -> TypeGuard[TreeCacheTup]:
+#     return isinstance(inp[0], bytes) and isinstance(inp[1], int) and isinstance([inp], str)
 
 #--------------------------------------------------------
 
diff --git a/git/refs/reference.py b/git/refs/reference.py
index f584bb54d..646622816 100644
--- a/git/refs/reference.py
+++ b/git/refs/reference.py
@@ -8,7 +8,7 @@
 # typing ------------------------------------------------------------------
 
 from typing import Any, Callable, Iterator, List, Match, Optional, Tuple, Type, TypeVar, Union, TYPE_CHECKING  # NOQA
-from git.types import Commit_ish, PathLike, TBD, Literal, TypeGuard, _T                                  # NOQA
+from git.types import Commit_ish, PathLike, TBD, Literal, _T                                  # NOQA
 
 if TYPE_CHECKING:
     from git.repo import Repo
diff --git a/git/refs/symbolic.py b/git/refs/symbolic.py
index 426d40d44..0e9dad5cc 100644
--- a/git/refs/symbolic.py
+++ b/git/refs/symbolic.py
@@ -24,7 +24,7 @@
 # typing ------------------------------------------------------------------
 
 from typing import Any, Iterator, List, Match, Optional, Tuple, Type, TypeVar, Union, TYPE_CHECKING  # NOQA
-from git.types import Commit_ish, PathLike, TBD, Literal, TypeGuard                                               # NOQA
+from git.types import Commit_ish, PathLike, TBD, Literal                                               # NOQA
 
 if TYPE_CHECKING:
     from git.repo import Repo
diff --git a/git/remote.py b/git/remote.py
index d903552f8..11007cb68 100644
--- a/git/remote.py
+++ b/git/remote.py
@@ -23,6 +23,7 @@
 )
 
 from .config import (
+    GitConfigParser,
     SectionConstraint,
     cp,
 )
@@ -37,9 +38,9 @@
 # typing-------------------------------------------------------
 
 from typing import (Any, Callable, Dict, Iterator, List, NoReturn, Optional, Sequence,  # NOQA[TC002]
-                    TYPE_CHECKING, Type, Union, overload)
+                    TYPE_CHECKING, Type, Union, cast, overload)
 
-from git.types import PathLike, Literal, TBD, TypeGuard, Commit_ish     # NOQA[TC002]
+from git.types import PathLike, Literal, TBD, Commit_ish     # NOQA[TC002]
 
 if TYPE_CHECKING:
     from git.repo.base import Repo
@@ -50,8 +51,8 @@
 flagKeyLiteral = Literal[' ', '!', '+', '-', '*', '=', 't', '?']
 
 
-def is_flagKeyLiteral(inp: str) -> TypeGuard[flagKeyLiteral]:
-    return inp in [' ', '!', '+', '-', '=', '*', 't', '?']
+# def is_flagKeyLiteral(inp: str) -> TypeGuard[flagKeyLiteral]:
+#     return inp in [' ', '!', '+', '-', '=', '*', 't', '?']
 
 
 # -------------------------------------------------------------
@@ -342,8 +343,8 @@ def _from_line(cls, repo: 'Repo', line: str, fetch_line: str) -> 'FetchInfo':
         # parse lines
         remote_local_ref_str: str
         control_character, operation, local_remote_ref, remote_local_ref_str, note = match.groups()
-        assert is_flagKeyLiteral(control_character), f"{control_character}"
-
+        # assert is_flagKeyLiteral(control_character), f"{control_character}"
+        control_character = cast(flagKeyLiteral, control_character)
         try:
             _new_hex_sha, _fetch_operation, fetch_note = fetch_line.split("\t")
             ref_type_name, fetch_note = fetch_note.split(' ', 1)
@@ -911,7 +912,7 @@ def push(self, refspec: Union[str, List[str], None] = None,
         return self._get_push_info(proc, progress)
 
     @ property
-    def config_reader(self) -> SectionConstraint:
+    def config_reader(self) -> SectionConstraint[GitConfigParser]:
         """
         :return:
             GitConfigParser compatible object able to read options for only our remote.
diff --git a/git/repo/base.py b/git/repo/base.py
index 64f32bd38..a57172c6c 100644
--- a/git/repo/base.py
+++ b/git/repo/base.py
@@ -36,7 +36,7 @@
 
 # typing ------------------------------------------------------
 
-from git.types import TBD, PathLike, Lit_config_levels, Commit_ish, Tree_ish, is_config_level
+from git.types import TBD, PathLike, Lit_config_levels, Commit_ish, Tree_ish
 from typing import (Any, BinaryIO, Callable, Dict,
                     Iterator, List, Mapping, Optional, Sequence,
                     TextIO, Tuple, Type, Union,
@@ -482,7 +482,8 @@ def _get_config_path(self, config_level: Lit_config_levels) -> str:
 
         raise ValueError("Invalid configuration level: %r" % config_level)
 
-    def config_reader(self, config_level: Optional[Lit_config_levels] = None) -> GitConfigParser:
+    def config_reader(self, config_level: Optional[Lit_config_levels] = None
+                      ) -> GitConfigParser:
         """
         :return:
             GitConfigParser allowing to read the full git configuration, but not to write it
@@ -498,12 +499,14 @@ def config_reader(self, config_level: Optional[Lit_config_levels] = None) -> Git
             unknown, instead the global path will be used."""
         files = None
         if config_level is None:
-            files = [self._get_config_path(f) for f in self.config_level if is_config_level(f)]
+            files = [self._get_config_path(cast(Lit_config_levels, f))
+                     for f in self.config_level if cast(Lit_config_levels, f)]
         else:
             files = [self._get_config_path(config_level)]
         return GitConfigParser(files, read_only=True, repo=self)
 
-    def config_writer(self, config_level: Lit_config_levels = "repository") -> GitConfigParser:
+    def config_writer(self, config_level: Lit_config_levels = "repository"
+                      ) -> GitConfigParser:
         """
         :return:
             GitConfigParser allowing to write values of the specified configuration file level.
diff --git a/git/types.py b/git/types.py
index 53f0f1e4e..ccaffef3e 100644
--- a/git/types.py
+++ b/git/types.py
@@ -10,12 +10,13 @@
 if sys.version_info[:2] >= (3, 8):
     from typing import Final, Literal, SupportsIndex, TypedDict, Protocol, runtime_checkable  # noqa: F401
 else:
-    from typing_extensions import Final, Literal, SupportsIndex, TypedDict, Protocol, runtime_checkable  # noqa: F401
+    from typing_extensions import (Final, Literal, SupportsIndex,                           # noqa: F401
+                                   TypedDict, Protocol, runtime_checkable)  # noqa: F401
 
-if sys.version_info[:2] >= (3, 10):
-    from typing import TypeGuard  # noqa: F401
-else:
-    from typing_extensions import TypeGuard  # noqa: F401
+# if sys.version_info[:2] >= (3, 10):
+#     from typing import TypeGuard  # noqa: F401
+# else:
+#     from typing_extensions import TypeGuard  # noqa: F401
 
 
 if sys.version_info[:2] < (3, 9):
@@ -41,9 +42,9 @@
 Lit_config_levels = Literal['system', 'global', 'user', 'repository']
 
 
-def is_config_level(inp: str) -> TypeGuard[Lit_config_levels]:
-    # return inp in get_args(Lit_config_level)  # only py >= 3.8
-    return inp in ("system", "user", "global", "repository")
+# def is_config_level(inp: str) -> TypeGuard[Lit_config_levels]:
+#     # return inp in get_args(Lit_config_level)  # only py >= 3.8
+#     return inp in ("system", "user", "global", "repository")
 
 
 ConfigLevels_Tup = Tuple[Literal['system'], Literal['user'], Literal['global'], Literal['repository']]
diff --git a/requirements.txt b/requirements.txt
index 80d6b1b44..a20310fb2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
 gitdb>=4.0.1,<5
-typing-extensions>=3.10.0.0;python_version<"3.10"
+typing-extensions>=3.7.4.3;python_version<"3.10"