diff --git a/doc/maintainers.md b/doc/maintainers.md
index 32aa64dce1..57a4d93bdc 100644
--- a/doc/maintainers.md
+++ b/doc/maintainers.md
@@ -327,9 +327,6 @@ have commit right, others don't.
 * https://rubygems.org/gems/weakref
 
 ### Extensions
-#### ext/bigdecimal
-* Kenta Murata (mrkn) https://github.com/ruby/bigdecimal
-* https://rubygems.org/gems/bigdecimal
 
 #### ext/cgi
 * Nobuyoshi Nakada (nobu)
@@ -481,6 +478,9 @@ have commit right, others don't.
 #### lib/base64.rb
 * https://github.com/ruby/base64
 
+#### ext/bigdecimal
+* https://rubygems.org/gems/bigdecimal
+
 ## Platform Maintainers
 ### mswin64 (Microsoft Windows)
 * NAKAMURA Usaku (usa)
diff --git a/doc/standard_library.rdoc b/doc/standard_library.rdoc
index 68fc34de01..0d7bf45bf3 100644
--- a/doc/standard_library.rdoc
+++ b/doc/standard_library.rdoc
@@ -82,7 +82,6 @@ WeakRef:: Allows a referenced object to be garbage-collected
 
 == Extensions
 
-BigDecimal:: Provides arbitrary-precision floating point decimal arithmetic
 Date:: A subclass of Object includes Comparable module for handling dates
 DateTime:: Subclass of Date to handling dates, hours, minutes, seconds, offsets
 Digest:: Provides a framework for message digest libraries
@@ -130,3 +129,4 @@ Racc:: A LALR(1) parser generator written in Ruby.
 Mutex_m:: Mixin to extend objects to be handled like a Mutex
 GetoptLong:: Parse command line options similar to the GNU C getopt_long()
 Base64:: Support for encoding and decoding binary data using a Base64 representation
+BigDecimal:: Provides arbitrary-precision floating point decimal arithmetic