diff --git a/aider/repo.py b/aider/repo.py
index b6ca1f00e..8bc44f006 100644
--- a/aider/repo.py
+++ b/aider/repo.py
@@ -206,7 +206,7 @@ class GitRepo:
         if not self.aider_ignore_file or not self.aider_ignore_file.is_file():
             return fnames
 
-        mtime = self.aider_ignore_file.stat().st_mtime
+        mtime = self.aider_ignore_file.stat().st_mtime_ns
 
         if mtime != self.aider_ignore_ts:
             self.aider_ignore_ts = mtime