diff --git a/ChangeLog b/ChangeLog
index abf3ec3c30..648ef8c89f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Jul 16 17:41:28 2009  Koichi Sasada  <ko1@atdot.net>
+
+	* vm_method.c (rb_alias): fix a case which try non-existing method alias.
+
+	* test/ruby/test_alias.rb: add a test.
+
 Thu Jul 16 15:52:25 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* bignum.c (rb_big_new, rb_bigzero_p), range.c (rb_range_values):
diff --git a/test/ruby/test_alias.rb b/test/ruby/test_alias.rb
index 10fd8f1112..f66c4a6340 100644
--- a/test/ruby/test_alias.rb
+++ b/test/ruby/test_alias.rb
@@ -61,4 +61,12 @@ class TestAlias < Test::Unit::TestCase
     }.call
     assert_raise(SecurityError) { d.mm }
   end
+
+  def test_nonexistmethod
+    assert_raise(NameError){
+      Class.new{
+        alias_method :foobarxyzzy, :barbaz
+      }
+    }
+  end
 end
diff --git a/vm_method.c b/vm_method.c
index b85351a671..4b747e9d52 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -814,10 +814,9 @@ rb_alias(VALUE klass, ID name, ID def)
     if (!orig_me || orig_me->type == VM_METHOD_TYPE_UNDEF) {
 	if (TYPE(klass) == T_MODULE) {
 	    orig_me = search_method(rb_cObject, def);
-
-	    if (!orig_me || !orig_me->type == VM_METHOD_TYPE_UNDEF) {
-		rb_print_undef(klass, def, 0);
-	    }
+	}
+	if (!orig_me || !orig_me->type == VM_METHOD_TYPE_UNDEF) {
+	    rb_print_undef(klass, def, 0);
 	}
     }
     if (FL_TEST(klass, FL_SINGLETON)) {