diff --git a/ChangeLog b/ChangeLog
index 3890d33492..788724739c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Jul 13 15:53:25 2014  Eric Wong  <e@80x24.org>
+
+	* vm_core.h (struct rb_iseq_struct): stack_max is uint32_t
+
 Sun Jul 13 10:56:26 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in (rb_cv_broken_backtrace): exit with failure
diff --git a/vm_core.h b/vm_core.h
index 63e53a5d11..c71b83c70d 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -204,6 +204,7 @@ struct rb_iseq_struct {
 	ISEQ_TYPE_MAIN,
 	ISEQ_TYPE_DEFINED_GUARD
     } type;              /* instruction sequence type */
+    uint32_t stack_max; /* for stack overflow check */
 
     rb_iseq_location_t location;
 
@@ -271,8 +272,6 @@ struct rb_iseq_struct {
     int arg_keyword_required;
     ID *arg_keyword_table;
 
-    size_t stack_max; /* for stack overflow check */
-
     /* catch table */
     struct iseq_catch_table_entry *catch_table;
     int catch_table_size;