1 files changed, 1 insertions, 1 deletions
diff --git a/sphinx/io.py b/sphinx/io.py
index b9e6147ff..f2a0369ad 100644
--- a/sphinx/io.py
+++ b/sphinx/io.py
@@ -212,7 +212,7 @@ def create_publisher(app: Sphinx, filetype: str) -> Publisher:
         parser=parser,
         writer=SphinxDummyWriter(),
         source_class=SphinxFileInput,
-        destination=NullOutput()
+        destination=NullOutput(),
     )
     # Propagate exceptions by default when used programmatically:
     defaults = {"traceback": True, **app.env.settings}