diff --git a/python/lsst/pipe/base/formatters/pexConfig.py b/python/lsst/pipe/base/formatters/pexConfig.py
index b4b58503e..ba8f82cbc 100644
--- a/python/lsst/pipe/base/formatters/pexConfig.py
+++ b/python/lsst/pipe/base/formatters/pexConfig.py
@@ -51,4 +51,4 @@ def read_from_stream(
         return Config._fromPython(stream.read().decode())
 
     def write_local_file(self, in_memory_dataset: Any, uri: ResourcePath) -> None:
-        in_memory_dataset.save(uri.path)
+        in_memory_dataset.save(uri.ospath)