diff --git a/ChangeLog b/ChangeLog
index 9eccd7e35b..5ee8ec32c2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jun 18 01:51:10 2008  Hidetoshi NAGAI  <nagai@ai.kyutech.ac.jp>
+
+	* ext/tk/lib/multi-tk.rb: cannot access class variable from
+	  singleton method. 
+
 Wed Jun 18 00:03:33 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* dir.c (Init_Dir): dir_foreach() takes variable argument.
diff --git a/ext/tk/lib/multi-tk.rb b/ext/tk/lib/multi-tk.rb
index 4f39874d30..4bc89a8147 100644
--- a/ext/tk/lib/multi-tk.rb
+++ b/ext/tk/lib/multi-tk.rb
@@ -2214,11 +2214,12 @@ end
 
 # event loop
 # all master/slave IPs are controled by only one event-loop
-class << MultiTkIp
-  def default_master?
+class MultiTkIp
+  def self.default_master?
     __getip == @@DEFAULT_MASTER
   end
-
+end
+class << MultiTkIp
   def mainloop(check_root = true)
     __getip.mainloop(check_root)
   end