diff --git a/ChangeLog b/ChangeLog
index 2b0536d23e..a9a62ad2fb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Sep 29 04:06:18 2009  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* include/ruby/st.h: include inttypes.h and stdint.h.
+
 Tue Sep 29 00:07:06 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* hash.c (rb_f_getenv, env_fetch): env string may be overwritten.
diff --git a/include/ruby/st.h b/include/ruby/st.h
index 76f240d1ca..fd9bc4e1ec 100644
--- a/include/ruby/st.h
+++ b/include/ruby/st.h
@@ -26,6 +26,13 @@ extern "C" {
 #include <stdlib.h>
 #endif
 
+#ifdef HAVE_STDINT_H
+# include <stdint.h>
+#endif
+#ifdef HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+
 #if SIZEOF_LONG == SIZEOF_VOIDP
 typedef unsigned long st_data_t;
 #elif SIZEOF_LONG_LONG == SIZEOF_VOIDP