diff --git a/src/mcp_client.py b/src/mcp_client.py
index c7c70a18..dd531059 100644
--- a/src/mcp_client.py
+++ b/src/mcp_client.py
@@ -165,17 +165,11 @@ def _is_allowed(path: Path) -> bool:
   # Allow current working directory and subpaths by default if no base_dirs
  cwd = Path.cwd().resolve()
  if not _base_dirs:
-  try:
-   rp.relative_to(cwd)
+  if rp.is_relative_to(cwd):
    return True
-  except ValueError:
-   pass
  for bd in _base_dirs:
-  try:
-   rp.relative_to(bd)
+  if rp.is_relative_to(bd):
    return True
-  except ValueError:
-   continue
  return False
 
 def _resolve_and_check(raw_path: str) -> tuple[Path | None, str]: