diff --git a/HISTORY.md b/HISTORY.md
index 8b8596486f8..1bc59993fe3 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -4,6 +4,7 @@
 
 - Added `--dark-mode` to select colors suitable for a dark terminal background
 - Reorganized the `--help` output
+- Bugfix and tests around git filenames with unicode characters
 - Bugfix so that aider throws an exception when OpenAI returns InvalidRequest
 - Bugfix/improvement to /add and /drop to recurse selected directories
 - Bugfix for live diff output when using "whole" edit format
diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 2cab25d64c2..c0a16499a46 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -160,7 +160,7 @@ def __init__(
             self.abs_fnames = set([str(Path(fname).resolve()) for fname in fnames])
 
         if self.repo:
-            rel_repo_dir = os.path.relpath(self.repo.git_dir, os.getcwd())
+            rel_repo_dir = self.get_rel_repo_dir()
             self.io.tool_output(f"Git repo: {rel_repo_dir}")
         else:
             self.io.tool_output("Git repo: none")
@@ -210,6 +210,12 @@ def find_common_root(self):
 
         self.root = utils.safe_abs_path(self.root)
 
+    def get_rel_repo_dir(self):
+        try:
+            return os.path.relpath(self.repo.git_dir, os.getcwd())
+        except ValueError:
+            return self.repo.git_dir
+
     def add_rel_fname(self, rel_fname):
         self.abs_fnames.add(self.abs_root_path(rel_fname))
 
@@ -265,7 +271,7 @@ def set_repo(self, cmd_line_fnames):
                 new_files.append(relative_fname)
 
         if new_files:
-            rel_repo_dir = os.path.relpath(self.repo.git_dir, os.getcwd())
+            rel_repo_dir = self.get_rel_repo_dir()
 
             self.io.tool_output(f"Files not tracked in {rel_repo_dir}:")
             for fn in new_files:
@@ -964,9 +970,20 @@ def allowed_to_edit(self, path, write_content=None):
     def get_tracked_files(self):
         if not self.repo:
             return []
+
+        try:
+            commit = self.repo.head.commit
+        except ValueError:
+            return set()
+
+        files = []
+        for blob in commit.tree.traverse():
+            if blob.type == "blob":  # blob is a file
+                files.append(blob.path)
+
         # convert to appropriate os.sep, since git always normalizes to /
-        files = set(self.repo.git.ls_files().splitlines())
         res = set(str(Path(PurePosixPath(path))) for path in files)
+
         return res
 
     apply_update_errors = 0
diff --git a/aider/commands.py b/aider/commands.py
index 396c960b08a..60e2022039f 100644
--- a/aider/commands.py
+++ b/aider/commands.py
@@ -221,7 +221,8 @@ def completions_add(self, partial):
                 yield Completion(fname, start_position=-len(partial))
 
     def glob_filtered_to_repo(self, pattern):
-        raw_matched_files = Path(self.coder.root).glob(pattern)
+        raw_matched_files = list(Path(self.coder.root).glob(pattern))
+
         matched_files = []
         for fn in raw_matched_files:
             matched_files += expand_subdir(fn.relative_to(self.coder.root))
@@ -250,7 +251,10 @@ def cmd_add(self, args):
                     self.io.tool_error(f"No files to add matching pattern: {word}")
                 else:
                     if Path(word).exists():
-                        matched_files = [word]
+                        if Path(word).is_file():
+                            matched_files = [word]
+                        else:
+                            self.io.tool_error(f"Unable to add: {word}")
                     elif self.io.confirm_ask(
                         f"No files matched '{word}'. Do you want to create the file?"
                     ):
diff --git a/aider/repomap.py b/aider/repomap.py
index 6e9f2583465..7535838dcab 100644
--- a/aider/repomap.py
+++ b/aider/repomap.py
@@ -172,7 +172,10 @@ def split_path(self, path):
 
     def run_ctags(self, filename):
         # Check if the file is in the cache and if the modification time has not changed
-        file_mtime = os.path.getmtime(filename)
+        file_mtime = self.get_mtime(filename)
+        if file_mtime is None:
+            return []
+
         cache_key = filename
         if cache_key in self.TAGS_CACHE and self.TAGS_CACHE[cache_key]["mtime"] == file_mtime:
             return self.TAGS_CACHE[cache_key]["data"]
@@ -239,8 +242,17 @@ def load_ident_cache(self):
     def save_ident_cache(self):
         pass
 
+    def get_mtime(self, fname):
+        try:
+            return os.path.getmtime(fname)
+        except FileNotFoundError:
+            self.io.tool_error(f"File not found error: {fname}")
+
     def get_name_identifiers(self, fname, uniq=True):
-        file_mtime = os.path.getmtime(fname)
+        file_mtime = self.get_mtime(fname)
+        if file_mtime is None:
+            return set()
+
         cache_key = fname
         if cache_key in self.IDENT_CACHE and self.IDENT_CACHE[cache_key]["mtime"] == file_mtime:
             idents = self.IDENT_CACHE[cache_key]["data"]
diff --git a/tests/test_coder.py b/tests/test_coder.py
index c4f95e06f64..ea3b62d8627 100644
--- a/tests/test_coder.py
+++ b/tests/test_coder.py
@@ -1,8 +1,10 @@
+import os
 import tempfile
 import unittest
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
+import git
 import openai
 import requests
 
@@ -29,9 +31,9 @@ def test_check_for_file_mentions(self):
         coder = Coder.create(models.GPT4, None, mock_io, openai_api_key="fake_key")
 
         # Mock the git repo
-        mock_repo = MagicMock()
-        mock_repo.git.ls_files.return_value = "file1.txt\nfile2.py"
-        coder.repo = mock_repo
+        mock = MagicMock()
+        mock.return_value = set(["file1.txt", "file2.py"])
+        coder.get_tracked_files = mock
 
         # Call the check_for_file_mentions method
         coder.check_for_file_mentions("Please check file1.txt and file2.py")
@@ -75,10 +77,9 @@ def test_check_for_filename_mentions_of_longer_paths(self):
         # Initialize the Coder object with the mocked IO and mocked repo
         coder = Coder.create(models.GPT4, None, mock_io, openai_api_key="fake_key")
 
-        # Mock the git repo
-        mock_repo = MagicMock()
-        mock_repo.git.ls_files.return_value = "file1.txt\nfile2.py"
-        coder.repo = mock_repo
+        mock = MagicMock()
+        mock.return_value = set(["file1.txt", "file2.py"])
+        coder.get_tracked_files = mock
 
         # Call the check_for_file_mentions method
         coder.check_for_file_mentions("Please check file1.txt and file2.py")
@@ -102,10 +103,9 @@ def test_check_for_ambiguous_filename_mentions_of_longer_paths(self):
         # Initialize the Coder object with the mocked IO and mocked repo
         coder = Coder.create(models.GPT4, None, mock_io, openai_api_key="fake_key")
 
-        # Mock the git repo
-        mock_repo = MagicMock()
-        mock_repo.git.ls_files.return_value = "file1.txt\nother/file1.txt"
-        coder.repo = mock_repo
+        mock = MagicMock()
+        mock.return_value = set(["file1.txt", "other/file1.txt"])
+        coder.get_tracked_files = mock
 
         # Call the check_for_file_mentions method
         coder.check_for_file_mentions("Please check file1.txt!")
@@ -352,11 +352,58 @@ def test_run_with_invalid_request_error(self, mock_chat_completion_create):
         coder = Coder.create(models.GPT4, None, mock_io, openai_api_key="fake_key")
 
         # Set up the mock to raise InvalidRequestError
-        mock_chat_completion_create.side_effect = openai.error.InvalidRequestError("Invalid request", "param")
+        mock_chat_completion_create.side_effect = openai.error.InvalidRequestError(
+            "Invalid request", "param"
+        )
 
         # Call the run method and assert that InvalidRequestError is raised
         with self.assertRaises(openai.error.InvalidRequestError):
             coder.run(with_message="hi")
 
+    def test_get_tracked_files(self):
+        # Create a temporary directory
+        tempdir = Path(tempfile.mkdtemp())
+
+        # Initialize a git repository in the temporary directory and set user name and email
+        repo = git.Repo.init(tempdir)
+        repo.config_writer().set_value("user", "name", "Test User").release()
+        repo.config_writer().set_value("user", "email", "testuser@example.com").release()
+
+        # Create three empty files and add them to the git repository
+        filenames = ["README.md", "subdir/fänny.md", "systemüber/blick.md", 'file"with"quotes.txt']
+        created_files = []
+        for filename in filenames:
+            file_path = tempdir / filename
+            try:
+                file_path.parent.mkdir(parents=True, exist_ok=True)
+                file_path.touch()
+                repo.git.add(str(file_path))
+                created_files.append(Path(filename))
+            except OSError:
+                # windows won't allow files with quotes, that's ok
+                self.assertIn('"', filename)
+                self.assertEqual(os.name, "nt")
+
+        self.assertTrue(len(created_files) >= 3)
+
+        repo.git.commit("-m", "added")
+
+        # Create a Coder object on the temporary directory
+        coder = Coder.create(
+            models.GPT4,
+            None,
+            io=InputOutput(),
+            openai_api_key="fake_key",
+            fnames=[str(tempdir / filenames[0])],
+        )
+
+        tracked_files = coder.get_tracked_files()
+
+        # On windows, paths will come back \like\this, so normalize them back to Paths
+        tracked_files = [Path(fn) for fn in tracked_files]
+
+        # Assert that coder.get_tracked_files() returns the three filenames
+        self.assertEqual(set(tracked_files), set(created_files))
+
     if __name__ == "__main__":
         unittest.main()