diff --git a/ChangeLog b/ChangeLog
index c34f3a0ca0..13cecb8522 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue May 27 16:58:12 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
+
+	* test/test_timeout.rb (test_timeout): inverted test condition.
+	  [Bug #8523]
+
 Tue May 27 12:24:22 2014  Tanaka Akira  <akr@fsij.org>
 
 	* test/lib/minitest/unit.rb: Show leaked file descriptors.
diff --git a/test/test_timeout.rb b/test/test_timeout.rb
index 117c1402fa..e350762637 100644
--- a/test/test_timeout.rb
+++ b/test/test_timeout.rb
@@ -13,15 +13,15 @@ class TestTimeout < Test::Unit::TestCase
   def test_timeout
     flag = true
     Thread.start {
-      sleep 0.01
+      sleep 1
       flag = false
     }
-    assert_nothing_raised("[ruby-dev:38319]") do
-      Timeout.timeout(1) {
+    assert_raise(Timeout::Error, "[ruby-dev:38319]") do
+      Timeout.timeout(0.1) {
         Thread.pass while flag
       }
     end
-    assert !flag, "[ruby-dev:38319]"
+    assert flag, "[ruby-dev:38319]"
   end
 
   def test_cannot_convert_into_time_interval