diff --git a/ChangeLog b/ChangeLog
index 3bc5e71194..f7b0032fa0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Nov  6 21:16:51 2013  Masaki Matsushita  <glass.saga@gmail.com>
+
+	* array.c (rb_ary_shift_m): use RARRAY_PTR_USE() without WB because
+	  there are not new relations.
+
 Wed Nov  6 21:05:20 2013  Masaki Matsushita  <glass.saga@gmail.com>
 
 	* array.c (rb_ary_reverse): use RARRAY_PTR_USE().
diff --git a/array.c b/array.c
index 2a85772c97..f1919fd1fe 100644
--- a/array.c
+++ b/array.c
@@ -1070,7 +1070,9 @@ rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
         ARY_INCREASE_PTR(ary, n);
     }
     else {
-	MEMMOVE(RARRAY_PTR(ary), RARRAY_PTR(ary)+n, VALUE, RARRAY_LEN(ary)-n);
+	RARRAY_PTR_USE(ary, ptr, {
+	    MEMMOVE(ptr, ptr + n, VALUE, RARRAY_LEN(ary)-n);
+	}); /* WB: no new reference */
     }
     ARY_INCREASE_LEN(ary, -n);