diff --git a/ChangeLog b/ChangeLog
index 7fdbb03862..702f8736bd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Jun 14 06:17:47 2012  Eric Hodel  <drbrain@segment7.net>
+
+	* lib/observer.rb:  Update broken link to the Programming Ruby book.
+	  Patch by Zachary Scott.  [ruby-trunk - Bug #6536]
+	* lib/drb/drb.rb:  ditto.
+
 Thu Jun 14 05:23:05 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* regparse.c (PFETCH_READY): suppress Wunused-but-set-variable.
diff --git a/lib/drb/drb.rb b/lib/drb/drb.rb
index 69456b1db2..217b5963ec 100644
--- a/lib/drb/drb.rb
+++ b/lib/drb/drb.rb
@@ -44,7 +44,7 @@
 # [http://www.eng.cse.dmu.ac.uk/~hgs/ruby/dRuby/]
 #   Links to English-language Ruby material collected by Hugh Sasse.
 #
-# [http://www.rubycentral.com/book/ospace.html]
+# [http://www.ruby-doc.org/docs/ProgrammingRuby/html/ospace.html]
 #   The chapter from *Programming* *Ruby* by Dave Thomas and Andy Hunt
 #   which discusses dRuby.
 #
diff --git a/lib/observer.rb b/lib/observer.rb
index a5d0dc0f4e..688b1f556b 100644
--- a/lib/observer.rb
+++ b/lib/observer.rb
@@ -1,7 +1,7 @@
 #
 # Implementation of the _Observer_ object-oriented design pattern.  The
 # following documentation is copied, with modifications, from "Programming
-# Ruby", by Hunt and Thomas; http://www.rubycentral.com/book/lib_patterns.html.
+# Ruby", by Hunt and Thomas; http://www.ruby-doc.org/docs/ProgrammingRuby/html/lib_patterns.html.
 #
 # See Observable for more info.