diff --git a/class.c b/class.c
index 350e2cc31b..43530c9461 100644
--- a/class.c
+++ b/class.c
@@ -1896,7 +1896,7 @@ rb_get_kwargs(VALUE keyword_hash, const ID *table, int required, int optional, V
 	}
     }
     if (!rest && keyword_hash) {
-	if (RHASH_SIZE(keyword_hash) > (unsigned int)j) {
+	if (RHASH_SIZE(keyword_hash) > (unsigned int)(values ? 0 : j)) {
 	    unknown_keyword_error(keyword_hash, table, required+optional);
 	}
     }
diff --git a/test/ruby/test_keyword.rb b/test/ruby/test_keyword.rb
index 1a7955dbcf..bcb93a6348 100644
--- a/test/ruby/test_keyword.rb
+++ b/test/ruby/test_keyword.rb
@@ -546,6 +546,13 @@ class TestKeywordArguments < Test::Unit::TestCase
     }
   end
 
+  def test_unknown_keyword
+    bug13004 = '[ruby-dev:49893] [Bug #13004]'
+    assert_raise_with_message(ArgumentError, /unknown keyword: invalid-argument/, bug13004) {
+      [].sample(random: nil, "invalid-argument": nil)
+    }
+  end
+
   def test_super_with_anon_restkeywords
     bug10659 = '[ruby-core:67157] [Bug #10659]'