diff --git a/doc/source/conf.py b/doc/source/conf.py
index 90bb0872971..165a17cc8d2 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -219,7 +219,7 @@ def visit_desc_content(self, node: Element) -> None:
 nbsphinx_execute = "always"
 nbsphinx_custom_formats = {
     ".mystnb": ["jupytext.reads", {"fmt": "mystnb"}],
-    ".sp.py":
+    ".sp.py",
 }
 nbsphinx_thumbnails = {
     "examples/00_EDB/00_create_via": "_static/diff_via.png",