diff --git a/docs/source/guide/config.rst b/docs/source/guide/config.rst
index 5b1883f7..8108b561 100644
--- a/docs/source/guide/config.rst
+++ b/docs/source/guide/config.rst
@@ -60,6 +60,7 @@ Projects that use the Meddlr library should extend the default config in their o
    def add_new_fields(cfg):
       cfg.NEW_FIELD = 0
       cfg.NEW_FIELD_STR = "default"
+      return cfg
    
    cfg = get_cfg()
    cfg = add_new_fields(cfg)
@@ -86,4 +87,4 @@ Default Fields in Meddlr
    .. csv-table:: Meddlr default config
       :file: ../../assets/temp/config-docs.csv
       :widths: 30, 70
-      :header-rows: 1
\ No newline at end of file
+      :header-rows: 1