diff --git a/site/docs/configuration.md b/site/docs/configuration.md
index c94656db..96dda3c1 100644
--- a/site/docs/configuration.md
+++ b/site/docs/configuration.md
@@ -330,6 +330,7 @@ kramdown:
   toc_levels: 1..6
   smart_quotes: lsquo,rsquo,ldquo,rdquo
   use_coderay: false
+  input: GFM
 
   coderay:
     coderay_wrap: div