diff --git a/ChangeLog b/ChangeLog
index 45b8977a31..343684cd39 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Nov 30 21:22:11 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* dir.c (dir_initialize): check unknown keywords.  [ruby-dev:47152]
+	  [Bug #8060]
+
 Sat Nov 30 18:05:38 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/win32ole/win32ole.c (hash2named_arg): correct declaration to fix
diff --git a/dir.c b/dir.c
index e3a74c18b0..99b1caa851 100644
--- a/dir.c
+++ b/dir.c
@@ -424,17 +424,20 @@ dir_initialize(int argc, VALUE *argv, VALUE dir)
     struct dir_data *dp;
     rb_encoding  *fsenc;
     VALUE dirname, opt, orig;
-    static VALUE sym_enc;
+    static ID keyword_ids[1];
 
-    if (!sym_enc) {
-	sym_enc = ID2SYM(rb_intern("encoding"));
+    if (!keyword_ids[0]) {
+	keyword_ids[0] = rb_intern("encoding");
     }
+
     fsenc = rb_filesystem_encoding();
 
     rb_scan_args(argc, argv, "1:", &dirname, &opt);
 
     if (!NIL_P(opt)) {
-	VALUE enc = rb_hash_aref(opt, sym_enc);
+	VALUE enc;
+	rb_check_keyword_opthash(opt, keyword_ids, 0, 1);
+	enc = rb_hash_aref(opt, ID2SYM(keyword_ids[0]));
 	if (!NIL_P(enc)) {
 	    fsenc = rb_to_encoding(enc);
 	}
diff --git a/test/ruby/test_dir.rb b/test/ruby/test_dir.rb
index 0948ae748d..7a46c07abe 100644
--- a/test/ruby/test_dir.rb
+++ b/test/ruby/test_dir.rb
@@ -200,6 +200,13 @@ class TestDir < Test::Unit::TestCase
     end
   end
 
+  def test_unknown_keywords
+    bug8060 = '[ruby-dev:47152] [Bug #8060]'
+    assert_raise_with_message(ArgumentError, /unknown keyword/, bug8060) do
+      Dir.open(@root, xawqij: "a") {}
+    end
+  end
+
   def test_symlink
     begin
       ["dummy", *?a..?z].each do |f|