diff --git a/ChangeLog b/ChangeLog
index fecacc5df4..ac0717b05c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Tue Jun 24 05:40:41 2014  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* nacl/nacl-config.rb: Use File.exist? instead of executable?
+	  for irt_core. Recent nacl_sdk has non-executable irt_core.
+	  Patch by Shinichiro Hamaji.
+	  [Fixes GH-529] https://github.com/ruby/ruby/pull/529
+
 Tue Jun 24 03:52:35 2014  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* lib/uri/mailto.rb: support RFC6068.
diff --git a/nacl/nacl-config.rb b/nacl/nacl-config.rb
old mode 100644
new mode 100755
index b90c9ed100..2da05c0847
--- a/nacl/nacl-config.rb
+++ b/nacl/nacl-config.rb
@@ -34,7 +34,7 @@ module NaClConfig
   IRT_CORE = [
     File.join(SDK_ROOT, 'toolchain', config['NACL_TOOLCHAIN'], 'bin', "irt_core_#{cpu_nick}.nexe"),
     File.join(SDK_ROOT, 'tools', "irt_core_#{cpu_nick}.nexe")
-  ].find{|path| File.executable?(path)} or raise "No irt_core found"
+  ].find{|path| File.exist?(path)} or raise "No irt_core found"
   RUNNABLE_LD = File.join(HOST_LIB, 'runnable-ld.so')
 
   module_function