diff --git a/src/ipymolstar/__init__.py b/src/ipymolstar/__init__.py
index 4f9e12c..eba18a1 100644
--- a/src/ipymolstar/__init__.py
+++ b/src/ipymolstar/__init__.py
@@ -6,3 +6,5 @@
     __version__ = "unknown"
 
 from ipymolstar.widget import PDBeMolstar
+
+__all__ = ["PDBeMolstar"]