diff --git a/ChangeLog b/ChangeLog
index 71db7648f4..e81d557d37 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Mar 20 13:05:16 2014  Koichi Sasada  <ko1@atdot.net>
+
+	* struct.c (rb_struct_alloc): use RARRAY_CONST_PTR() instead of
+	  RARRAY_PTR().
+
 Thu Mar 20 12:59:39 2014  Koichi Sasada  <ko1@atdot.net>
 
 	* include/ruby/intern.h (rb_obj_call_init, rb_class_new_instance):
diff --git a/struct.c b/struct.c
index c3dba62962..7da60dbad0 100644
--- a/struct.c
+++ b/struct.c
@@ -480,7 +480,7 @@ struct_alloc(VALUE klass)
 VALUE
 rb_struct_alloc(VALUE klass, VALUE values)
 {
-    return rb_class_new_instance(RARRAY_LENINT(values), RARRAY_PTR(values), klass);
+    return rb_class_new_instance(RARRAY_LENINT(values), RARRAY_CONST_PTR(values), klass);
 }
 
 VALUE