diff --git a/doc/maintainers.rdoc b/doc/maintainers.rdoc
index 268293a..8063bbf 100644
--- a/doc/maintainers.rdoc
+++ b/doc/maintainers.rdoc
@@ -348,6 +348,9 @@
   Nobuyuki Nakada (nobu)
   https://github.com/ruby/io-wait
   https://rubygems.org/gems/io-wait
+[ext/json]
+  NARUSE, Yui (naruse), Hiroshi SHIBATA (hsbt)
+  https://github.com/flori/json
 [ext/nkf]
   NARUSE, Yui (naruse)
   https://github.com/ruby/nkf
diff --git a/lib/json/.document b/lib/json/.document
new file mode 100644
index 0000000000..7ae6b614de
--- /dev/null
+++ b/lib/json/.document
@@ -0,0 +1,3 @@
+*.rb
+add/*.rb
+pure/*.rb