diff --git a/ChangeLog b/ChangeLog
index 9b41d05f9f..5fb481b179 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed May 28 16:41:59 2008  Akinori MUSHA  <knu@iDaemons.org>
+
+	* array.c (rb_ary_slice_bang): Call rb_ary_modify_check() at the
+	  beginning. [rubyspec]
+
 Wed May 28 16:12:44 2008  Akinori MUSHA  <knu@iDaemons.org>
 
 	* lib/webrick/httpservlet/cgihandler.rb (WEBrick::HTTPServlet::CGIHandler#do_GET):
diff --git a/array.c b/array.c
index 5dd172c157..39d2fbe931 100644
--- a/array.c
+++ b/array.c
@@ -1805,6 +1805,7 @@ rb_ary_slice_bang(int argc, VALUE *argv, VALUE ary)
     VALUE arg1, arg2;
     long pos, len, orig_len;
 
+    rb_ary_modify_check(ary);
     if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {
 	pos = NUM2LONG(arg1);
 	len = NUM2LONG(arg2);