diff --git a/ChangeLog b/ChangeLog
index fd96025466..ba13fb5b6a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Dec 26 12:52:36 2012  Keiju Ishitsuka  <keiju@ishitsuka.com>
+
+	* lib/irb/init.rb: change default debug level for
+	  irb[ruby-dev:46805], [Bug #6301].
+
 Wed Dec 26 11:54:11 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* configure.in: enable -fPIE when checking -pie for fixing
diff --git a/lib/irb/init.rb b/lib/irb/init.rb
index 2c3797f71f..826bcaf3ac 100644
--- a/lib/irb/init.rb
+++ b/lib/irb/init.rb
@@ -115,7 +115,7 @@ module IRB # :nodoc:
 
     @CONF[:AT_EXIT] = []
 
-    @CONF[:DEBUG_LEVEL] = 1
+    @CONF[:DEBUG_LEVEL] = 0
   end
 
   def IRB.init_error