diff --git a/ChangeLog b/ChangeLog
index 976275c80c..dee82b003d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sun Jan  9 16:31:34 2011  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
+
+	* lib/irb/locale.rb (IRB::Locale::LOCALE_NAME_RE): 
+	  some platoform has a locale without territory but with 
+	  encoding.
+	  (#each_sub_locale): ditto.
+
 Sun Jan  9 14:47:50 2011  TAKAO Kouji  <kouji@takao7.net>
 
 	* ext/readline/readline.c: apply a patch from Nobuyoshi Nakada.
diff --git a/lib/irb/locale.rb b/lib/irb/locale.rb
index b37ad08403..142b9a5951 100644
--- a/lib/irb/locale.rb
+++ b/lib/irb/locale.rb
@@ -13,16 +13,10 @@ module IRB
     @RCS_ID='-$Id$-'
 
     LOCALE_NAME_RE = %r[
-      (?<language>[[:alpha:]]{2})
-      (?:_
-       (?<territory>[[:alpha:]]{2,3})
-       (?:\.
-	(?<codeset>[^@]+)
-       )?
-      )?
-      (?:@
-       (?<modifier>.*)
-      )?
+      (?<language>[[:alpha:]]{2,3})
+      (?:_  (?<territory>[[:alpha:]]{2,3}) )?
+      (?:\. (?<codeset>[^@]+) )?
+      (?:@  (?<modifier>.*) )?
     ]x
     LOCALE_DIR = "/lc/"
 
@@ -175,6 +169,10 @@ module IRB
 	  yield "#{@lang}_#{@territory}@#{@modifier}" if @modifier
 	  yield "#{@lang}_#{@territory}"
 	end
+        if @encoding_name
+          yield "#{@lang}.#{@encoding_name}@#{@modifier}" if @modifier
+          yield "#{@lang}.#{@encoding_name}"
+        end
 	yield "#{@lang}@#{@modifier}" if @modifier
 	yield "#{@lang}"
       end