diff --git a/ChangeLog b/ChangeLog
index edf89f835b..36c4104018 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Apr 26 23:48:58 2013  Tanaka Akira  <akr@fsij.org>
+
+	* thread_pthread.c (ruby_init_stack): Add STACK_GROW_DIR_DETECTION.
+	  This fixes a compilation failure while cross-compiling for ARM.
+
 Fri Apr 26 23:32:09 2013  Kouhei Sutou  <kou@cozmixng.org>
 
 	* lib/rss/atom.rb (RSS::Atom::Entry): Fix indent of document comment.
diff --git a/thread_pthread.c b/thread_pthread.c
index 6c22870c1e..46a8652192 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -687,6 +687,7 @@ ruby_init_stack(volatile VALUE *addr
     /* it should be on co-routine (alternative stack). [Feature #2294] */
     {
 	void *start, *end;
+	STACK_GROW_DIR_DETECTION;
 
 	if (IS_STACK_DIR_UPPER()) {
 	    start = native_main_thread.stack_start;
diff --git a/version.h b/version.h
index a5ab9f85c2..c54dc97d0e 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.0.0"
 #define RUBY_RELEASE_DATE "2013-04-26"
-#define RUBY_PATCHLEVEL 171
+#define RUBY_PATCHLEVEL 172
 
 #define RUBY_RELEASE_YEAR 2013
 #define RUBY_RELEASE_MONTH 4