diff --git a/ChangeLog b/ChangeLog
index 4865ea32c7..5381342154 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Aug 26 09:49:50 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* array.c (rb_ary_shuffle_bang): check number of argument.
+
 Tue Aug 26 09:11:40 2010  Kenta Murata  <mrkn@mrkn.jp>
 
 	* ext/bigdecimal/bigdecimal.c (Init_bigdecimal,
diff --git a/array.c b/array.c
index a21f9ef51e..a2083210d3 100644
--- a/array.c
+++ b/array.c
@@ -3754,6 +3754,9 @@ rb_ary_shuffle_bang(int argc, VALUE *argv, VALUE ary)
     if (OPTHASH_GIVEN_P(opts)) {
 	randgen = rb_hash_lookup2(opts, sym_random, randgen);
     }
+    if (argc > 0) {
+	rb_raise(rb_eArgError, "wrong number of arguments (%d for 0)", argc);
+    }
     rb_ary_modify(ary);
     ptr = RARRAY_PTR(ary);
     while (i) {
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 4a8b700c77..4c3aba0589 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1893,6 +1893,7 @@ class TestArray < Test::Unit::TestCase
     end
 
     gen = Random.new(0)
+    assert_raise(ArgumentError) {[1, 2, 3].shuffle(1, random: gen)}
     srand(0)
     100.times do
       assert_equal([0, 1, 2].shuffle, [0, 1, 2].shuffle(random: gen))