diff --git a/ChangeLog b/ChangeLog
index c55354e9b7..fe06140357 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,7 @@
-Tue Jul 14 11:21:31 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Tue Jul 14 11:22:42 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/webrick/utils.rb (WEBrick::Utils::TimeoutHandler#register):
+	  notify the handler thread of new timeout registration.
 
 	* lib/webrick/utils.rb (WEBrick::Utils::TimeoutHandler#initialize):
 	  make sleep intervals adaptive than fixed period intervals.
diff --git a/lib/webrick/utils.rb b/lib/webrick/utils.rb
index c6da8449df..da6386c96c 100644
--- a/lib/webrick/utils.rb
+++ b/lib/webrick/utils.rb
@@ -153,7 +153,7 @@ module WEBrick
       # instead of creating the timeout handler directly.
       def initialize
         @timeout_info = Hash.new
-        Thread.start{
+        @watcher = Thread.start{
           while true
             now = Time.now
             wakeup = nil
@@ -194,8 +194,12 @@ module WEBrick
       # +exception+:: Exception to raise when timeout elapsed
       def register(thread, time, exception)
         @timeout_info[thread] ||= Array.new
-        @timeout_info[thread] << [time, exception]
-        return @timeout_info[thread].last.object_id
+        @timeout_info[thread] << (info = [time, exception])
+        begin
+          @watcher.wakeup
+        rescue ThreadError
+        end
+        return info.object_id
       end
 
       ##
diff --git a/test/webrick/test_utils.rb b/test/webrick/test_utils.rb
index 3ab4f2b126..9d135f7855 100644
--- a/test/webrick/test_utils.rb
+++ b/test/webrick/test_utils.rb
@@ -5,7 +5,7 @@ class TestWEBrickUtils < Test::Unit::TestCase
   def assert_expired(flag, m)
     if m == WEBrick::Utils
       handler = WEBrick::Utils::TimeoutHandler.instance
-      assert_equal(flag, handler.instance_eval{ @timeout_info.empty? })
+      assert_equal(flag, handler.instance_variable_get(:@timeout_info).empty?)
     end
   end
 
@@ -21,8 +21,8 @@ class TestWEBrickUtils < Test::Unit::TestCase
     m = WEBrick::Utils
     i = 0
     assert_raise(Timeout::Error){
-      m.timeout(2){
-        assert_raise(Timeout::Error){ m.timeout(1){ i += 1; sleep } }
+      m.timeout(0.02){
+        assert_raise(Timeout::Error){ m.timeout(0.01){ i += 1; sleep } }
         assert_expired(false, m)
         i += 1
         sleep
@@ -34,14 +34,14 @@ class TestWEBrickUtils < Test::Unit::TestCase
 
   def test_timeout_default_execption
     m = WEBrick::Utils
-    assert_raise(Timeout::Error){ m.timeout(0.1){ sleep } }
+    assert_raise(Timeout::Error){ m.timeout(0.01){ sleep } }
     assert_expired(true, m)
   end
 
   def test_timeout_custom_exception
     m = WEBrick::Utils
     ex = EX
-    assert_raise(ex){ m.timeout(0.1, ex){ sleep } }
+    assert_raise(ex){ m.timeout(0.01, ex){ sleep } }
     assert_expired(true, m)
   end
 
@@ -51,7 +51,7 @@ class TestWEBrickUtils < Test::Unit::TestCase
     i = 0
     assert_raise(ex){
       m.timeout(10){
-        m.timeout(1, ex){ i += 1; sleep }
+        m.timeout(0.01, ex){ i += 1; sleep }
       }
       sleep
     }
@@ -64,8 +64,8 @@ class TestWEBrickUtils < Test::Unit::TestCase
     ex = EX
     i = 0
     assert_raise(Timeout::Error){
-      m.timeout(1){
-        m.timeout(10, ex){ i += 1; sleep }
+      m.timeout(0.01){
+        m.timeout(1.0, ex){ i += 1; sleep }
       }
       sleep
     }