diff --git a/importlib_resources/__init__.py b/importlib_resources/__init__.py
index 0d029ab..ec4441c 100644
--- a/importlib_resources/__init__.py
+++ b/importlib_resources/__init__.py
@@ -7,7 +7,7 @@
     Anchor,
 )
 
-from .functional import (
+from ._functional import (
     contents,
     is_resource,
     open_binary,
diff --git a/importlib_resources/functional.py b/importlib_resources/_functional.py
similarity index 100%
rename from importlib_resources/functional.py
rename to importlib_resources/_functional.py