diff --git a/rich/jupyter.py b/rich/jupyter.py
index fef7bb8f..7cdcc9ca 100644
--- a/rich/jupyter.py
+++ b/rich/jupyter.py
@@ -31,7 +31,7 @@ class JupyterRenderable:
 class JupyterMixin:
     """Add to an Rich renderable to make it render in Jupyter notebook."""
 
-    __slots__ = []
+    __slots__ = ()
 
     def _repr_mimebundle_(
         self, include: Iterable[str], exclude: Iterable[str], **kwargs: Any