diff --git a/ChangeLog b/ChangeLog
index 2487728834..153543cd3f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Dec 10 21:00:30 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* array.c (rb_ary_slice_bang): should return nil if position out
+	  of range.  a patch from Akinori MUSHA <knu AT iDaemons.org>.
+	  [ruby-dev:32518]
+
 Mon Dec 10 19:02:52 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* re.c (rb_reg_match): should calculate offset by converted
diff --git a/array.c b/array.c
index 4eaf0c7ddc..30caf7b5da 100644
--- a/array.c
+++ b/array.c
@@ -1888,6 +1888,7 @@ rb_ary_slice_bang(int argc, VALUE *argv, VALUE ary)
       delete_pos_len:
 	if (pos < 0) {
 	    pos = RARRAY_LEN(ary) + pos;
+	    if (pos < 0) return Qnil;
 	}
 	arg2 = rb_ary_subseq(ary, pos, len);
 	rb_ary_splice(ary, pos, len, Qundef);	/* Qnil/rb_ary_new2(0) */