diff --git a/git/index/base.py b/git/index/base.py
index cda08de25..dd8f9aa2e 100644
--- a/git/index/base.py
+++ b/git/index/base.py
@@ -4,6 +4,7 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
+from contextlib import ExitStack
 import datetime
 import glob
 from io import BytesIO
@@ -352,27 +353,22 @@ def from_tree(cls, repo: "Repo", *treeish: Treeish, **kwargs: Any) -> "IndexFile
 
         # tmp file created in git home directory to be sure renaming
         # works - /tmp/ dirs could be on another device
-        tmp_index = tempfile.mktemp("", "", repo.git_dir)
-        arg_list.append("--index-output=%s" % tmp_index)
-        arg_list.extend(treeish)
-
-        # move current index out of the way - otherwise the merge may fail
-        # as it considers existing entries. moving it essentially clears the index.
-        # Unfortunately there is no 'soft' way to do it.
-        # The TemporaryFileSwap assure the original file get put back
-        if repo.git_dir:
-            index_handler = TemporaryFileSwap(join_path_native(repo.git_dir, "index"))
-        try:
+        with ExitStack() as stack:
+            tmp_index = stack.enter_context(tempfile.NamedTemporaryFile(dir=repo.git_dir))
+            arg_list.append("--index-output=%s" % tmp_index.name)
+            arg_list.extend(treeish)
+
+            # move current index out of the way - otherwise the merge may fail
+            # as it considers existing entries. moving it essentially clears the index.
+            # Unfortunately there is no 'soft' way to do it.
+            # The TemporaryFileSwap assure the original file get put back
+
+            stack.enter_context(TemporaryFileSwap(join_path_native(repo.git_dir, "index")))
             repo.git.read_tree(*arg_list, **kwargs)
-            index = cls(repo, tmp_index)
+            index = cls(repo, tmp_index.name)
             index.entries  # force it to read the file as we will delete the temp-file
-            del index_handler  # release as soon as possible
-        finally:
-            if osp.exists(tmp_index):
-                os.remove(tmp_index)
-        # END index merge handling
-
-        return index
+            return index
+            # END index merge handling
 
     # UTILITIES
     @unbare_repo
@@ -1156,7 +1152,6 @@ def checkout(
         unknown_lines = []
 
         def handle_stderr(proc: "Popen[bytes]", iter_checked_out_files: Iterable[PathLike]) -> None:
-
             stderr_IO = proc.stderr
             if not stderr_IO:
                 return None  # return early if stderr empty
diff --git a/git/index/util.py b/git/index/util.py
index bfc7fadd6..6cf838f3b 100644
--- a/git/index/util.py
+++ b/git/index/util.py
@@ -3,6 +3,7 @@
 import os
 import struct
 import tempfile
+from types import TracebackType
 
 from git.compat import is_win
 
@@ -11,7 +12,7 @@
 
 # typing ----------------------------------------------------------------------
 
-from typing import Any, Callable, TYPE_CHECKING
+from typing import Any, Callable, TYPE_CHECKING, Optional, Type
 
 from git.types import PathLike, _T
 
@@ -47,12 +48,21 @@ def __init__(self, file_path: PathLike) -> None:
         except OSError:
             pass
 
-    def __del__(self) -> None:
+    def __enter__(self) -> "TemporaryFileSwap":
+        return self
+
+    def __exit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_val: Optional[BaseException],
+        exc_tb: Optional[TracebackType],
+    ) -> bool:
         if osp.isfile(self.tmp_file_path):
             if is_win and osp.exists(self.file_path):
                 os.remove(self.file_path)
             os.rename(self.tmp_file_path, self.file_path)
-        # END temp file exists
+
+        return False
 
 
 # { Decorators