diff --git a/ChangeLog b/ChangeLog
index afde26c6e4..4aa48a9118 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Oct 30 21:12:45 2015  Kazuki Tsujimoto  <kazuki@callcc.net>
+
+	* gems/bundled_gems: update to power_assert 0.2.5.
+
 Fri Oct 30 19:29:52 2015  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (newobj_slowpath): do not need to use flags hack (commit miss).
diff --git a/gems/bundled_gems b/gems/bundled_gems
index beaf5aa69f..778d015f01 100644
--- a/gems/bundled_gems
+++ b/gems/bundled_gems
@@ -1,4 +1,4 @@
-power_assert 0.2.4
+power_assert 0.2.5
 test-unit 3.1.5
 minitest 5.8.2
 rake 10.4.2