diff --git a/ChangeLog b/ChangeLog
index 9503a99c7c..5089c4b04d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Jun 13 00:27:24 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* ext/dl/lib/dl.rb: don't require when already loaded.
+
 Sun Jun 13 00:02:56 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* ext/fiddle/closure.c (dealloc): workaround fix for libffi's
diff --git a/ext/dl/lib/dl.rb b/ext/dl/lib/dl.rb
index 168a18a55e..80d46b685a 100644
--- a/ext/dl/lib/dl.rb
+++ b/ext/dl/lib/dl.rb
@@ -1,7 +1,7 @@
 require 'dl.so'
 
 begin
-  require 'fiddle'
+  require 'fiddle' unless Object.const_defined?(:Fiddle)
 rescue LoadError
 end