diff --git a/docxtpl/__init__.py b/docxtpl/__init__.py
index 5559d4f..0f351d6 100644
--- a/docxtpl/__init__.py
+++ b/docxtpl/__init__.py
@@ -6,14 +6,24 @@
 """
 
 __version__ = "0.20.2"
+__all__ = (
+    "RP",
+    "DocxTemplate",
+    "InlineImage",
+    "Listing",
+    "R",
+    "RichText",
+    "RichTextParagraph",
+)
 
-# flake8: noqa
 from .inline_image import InlineImage
 from .listing import Listing
-from .richtext import RichText, R, RichTextParagraph, RP
+from .richtext import RP, R, RichText, RichTextParagraph
 from .template import DocxTemplate
 
 try:
     from .subdoc import Subdoc
+
+    __all__ += ("Subdoc",)
 except ImportError:
     pass