diff --git a/src/uwtools/drivers/fv3.py b/src/uwtools/drivers/fv3.py
index 816c95fab..6d6647376 100644
--- a/src/uwtools/drivers/fv3.py
+++ b/src/uwtools/drivers/fv3.py
@@ -67,7 +67,7 @@ def field_table(self):
         yield self._taskname(fn)
         path = self._rundir / fn
         yield asset(path, path.is_file)
-        yield filecopy(src=self._driver_config["field_table"]["base_file"], dst=path)
+        yield filecopy(src=Path(self._driver_config["field_table"]["base_file"]), dst=path)
 
     @tasks
     def files_copied(self):
diff --git a/src/uwtools/tests/drivers/test_fv3.py b/src/uwtools/tests/drivers/test_fv3.py
index 939f6bc13..59fde2e22 100644
--- a/src/uwtools/tests/drivers/test_fv3.py
+++ b/src/uwtools/tests/drivers/test_fv3.py
@@ -132,7 +132,7 @@ def test_FV3_field_table(driverobj):
     src.touch()
     dst = driverobj._rundir / "field_table"
     assert not dst.is_file()
-    driverobj._driver_config["field_table"] = {"base_file": src}
+    driverobj._driver_config["field_table"] = {"base_file": str(src)}
     driverobj.field_table()
     assert dst.is_file()