diff --git a/ChangeLog b/ChangeLog
index 84760bca15..24cf665203 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jan 27 23:29:36 2010  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* lib/thread.rb (ConditionVariable#wait, signal, broadcast): return
+	  self (for 1.8 compatibility).
+
 Wed Jan 27 23:27:54 2010  Keiju Ishitsuka  <keiju@emperor2.pendome>
 
 	* lib/matrix.rb: add exception Matrix::ErrOperationNotImplemented
diff --git a/lib/thread.rb b/lib/thread.rb
index 34c2a506d2..4f296bb8b3 100644
--- a/lib/thread.rb
+++ b/lib/thread.rb
@@ -70,6 +70,7 @@ class ConditionVariable
       end
       mutex.sleep timeout
     end
+    self
   end
 
   #
@@ -82,6 +83,7 @@ class ConditionVariable
     rescue ThreadError
       retry
     end
+    self
   end
 
   #
@@ -96,10 +98,11 @@ class ConditionVariable
     end
     for t in waiters0
       begin
-	t.run
+        t.run
       rescue ThreadError
       end
     end
+    self
   end
 end