diff --git a/doc/maintainers.rdoc b/doc/maintainers.rdoc
index 74ee6aaee0..8536a3fe82 100644
--- a/doc/maintainers.rdoc
+++ b/doc/maintainers.rdoc
@@ -97,6 +97,8 @@ Zachary Scott (zzak)
 [lib/jcode.rb]
   * 1.8: _unmaintained_
   * 1.9: _deprecated_
+[ext/json]
+  NARUSE, Yui (naruse)
 [lib/logger.rb]
   Naotoshi Seo (sonots)
 [lib/mathn.rb]
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