diff --git a/ChangeLog b/ChangeLog
index 788724739c..59058d5e1c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Jul 13 16:44:56 2014  Eric Wong  <e@80x24.org>
+
+	* vm_core.h (struct rb_call_info_struct): improve packing
+
 Sun Jul 13 15:53:25 2014  Eric Wong  <e@80x24.org>
 
 	* vm_core.h (struct rb_iseq_struct): stack_max is uint32_t
diff --git a/vm_core.h b/vm_core.h
index c71b83c70d..8a8ceeb981 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -141,8 +141,10 @@ typedef struct rb_call_info_struct {
     /* fixed at compile time */
     ID mid;
     VALUE flag;
-    int orig_argc;
     rb_iseq_t *blockiseq;
+    int orig_argc;
+
+    int argc; /* temporary for method calling */
 
     /* inline cache: keys */
     rb_serial_t method_state;
@@ -154,7 +156,6 @@ typedef struct rb_call_info_struct {
     VALUE defined_class;
 
     /* temporary values for method calling */
-    int argc;
     struct rb_block_struct *blockptr;
     VALUE recv;
     union {