diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 86dc20e81..35726dd92 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -100,6 +100,7 @@ class Coder:
         stream=True,
         use_git=True,
         voice_language=None,
+        aider_ignore_file=None,
     ):
         if not fnames:
             fnames = []
@@ -154,7 +155,7 @@ class Coder:
 
         if use_git:
             try:
-                self.repo = GitRepo(self.io, fnames, git_dname)
+                self.repo = GitRepo(self.io, fnames, git_dname, aider_ignore_file)
                 self.root = self.repo.root
             except FileNotFoundError:
                 self.repo = None
diff --git a/aider/main.py b/aider/main.py
index 620e17ace..f3461dd6e 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -305,10 +305,13 @@ def main(argv=None, input=None, output=None, force_git_root=None):
         default=True,
         help="Enable/disable adding .aider* to .gitignore (default: True)",
     )
+    default_aiderignore_file = (
+        os.path.join(git_root, ".aiderignore") if git_root else ".aiderignore"
+    )
     git_group.add_argument(
         "--aiderignore",
         metavar="AIDERIGNORE",
-        default=".aiderignore",
+        default=default_aiderignore_file,
         help="Specify the aider ignore file (default: .aiderignore in git root)",
     )
     git_group.add_argument(
@@ -507,6 +510,7 @@ def main(argv=None, input=None, output=None, force_git_root=None):
             stream=args.stream,
             use_git=args.git,
             voice_language=args.voice_language,
+            aider_ignore_file=args.aiderignore,
         )
     except ValueError as err:
         io.tool_error(str(err))
diff --git a/aider/repo.py b/aider/repo.py
index bc1c338ec..f3a3818d4 100644
--- a/aider/repo.py
+++ b/aider/repo.py
@@ -1,8 +1,8 @@
 import os
-import pathspec
 from pathlib import Path, PurePosixPath
 
 import git
+import pathspec
 
 from aider import models, prompts, utils
 from aider.sendchat import simple_send_with_retries
@@ -196,14 +196,14 @@ class GitRepo:
             for path in files
         )
 
-        return res
+        return self.filter_ignored_files(res)
 
     def filter_ignored_files(self, fnames):
         if not self.aider_ignore_file:
             return fnames
 
-        with open(self.aider_ignore_file, 'r') as f:
-            ignore_spec = pathspec.PathSpec.from_lines('gitwildmatch', f)
+        with open(self.aider_ignore_file, "r") as f:
+            ignore_spec = pathspec.PathSpec.from_lines("gitwildmatch", f)
 
         return [fname for fname in fnames if not ignore_spec.match_file(fname)]