diff --git a/aider/repo.py b/aider/repo.py
index 040f8156b..07a47592c 100644
--- a/aider/repo.py
+++ b/aider/repo.py
@@ -50,9 +50,9 @@ class GitRepo:
         self.root = utils.safe_abs_path(self.repo.working_tree_dir)
 
     def add_new_files(self, fnames):
-        cur_files = [Path(fn).resolve() for fn in self.get_tracked_files()]
+        cur_files = [str(Path(fn).resolve()) for fn in self.get_tracked_files()]
         for fname in fnames:
-            if Path(fname).resolve() in cur_files:
+            if str(Path(fname).resolve()) in cur_files:
                 continue
             if not Path(fname).exists():
                 continue
@@ -183,7 +183,10 @@ class GitRepo:
         files.extend(staged_files)
 
         # convert to appropriate os.sep, since git always normalizes to /
-        res = set(str(Path(PurePosixPath(path))) for path in files)
+        res = set(
+            str(Path(PurePosixPath((Path(self.root) / path).relative_to(self.root))))
+            for path in files
+        )
 
         return res
 
diff --git a/tests/test_repo.py b/tests/test_repo.py
index 8451ec309..aee78abdf 100644
--- a/tests/test_repo.py
+++ b/tests/test_repo.py
@@ -170,3 +170,27 @@ class TestRepo(unittest.TestCase):
             fnames = git_repo.get_tracked_files()
             self.assertIn(str(fname), fnames)
             self.assertIn(str(fname2), fnames)
+
+    def test_get_tracked_files_from_subdir(self):
+        with GitTemporaryDirectory():
+            # new repo
+            raw_repo = git.Repo()
+
+            # add it, but no commits at all in the raw_repo yet
+            fname = Path("subdir/new.txt")
+            fname.parent.mkdir()
+            fname.touch()
+            raw_repo.git.add(str(fname))
+
+            os.chdir(fname.parent)
+
+            git_repo = GitRepo(InputOutput(), None, None)
+
+            # better be there
+            fnames = git_repo.get_tracked_files()
+            self.assertIn(str(fname), fnames)
+
+            # commit it, better still be there
+            raw_repo.git.commit("-m", "new")
+            fnames = git_repo.get_tracked_files()
+            self.assertIn(str(fname), fnames)