diff --git a/stix2/workbench.py b/stix2/workbench.py
index c5aac6e..57474a9 100644
--- a/stix2/workbench.py
+++ b/stix2/workbench.py
@@ -106,7 +106,7 @@ STIX_OBJ_DOCS = """
 """.format(
     _environ.creator_of.__doc__,
     _environ.relationships.__doc__,
-    _environ.related_to.__doc__
+    _environ.related_to.__doc__,
 )