diff --git a/activesupport/lib/active_support/core_ext/hash/keys.rb b/activesupport/lib/active_support/core_ext/hash/keys.rb
index 87251388563e9..3c8a59f00a754 100644
--- a/activesupport/lib/active_support/core_ext/hash/keys.rb
+++ b/activesupport/lib/active_support/core_ext/hash/keys.rb
@@ -43,8 +43,8 @@ def symbolize_keys!
         alias_method :to_options,  :symbolize_keys
         alias_method :to_options!, :symbolize_keys!
 
-        def assert_valid_keys(valid_keys)
-          unknown_keys = keys - valid_keys
+        def assert_valid_keys(*valid_keys)
+          unknown_keys = keys - [valid_keys].flatten
           raise(ArgumentError, "Unknown key(s): #{unknown_keys.join(", ")}") unless unknown_keys.empty?
         end
       end
diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index 8addd895ccddd..f42b6fde2f12c 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -96,10 +96,12 @@ def test_indifferent_writing
   def test_assert_valid_keys
     assert_nothing_raised do
       { :failure => "stuff", :funny => "business" }.assert_valid_keys([ :failure, :funny ])
+      { :failure => "stuff", :funny => "business" }.assert_valid_keys(:failure, :funny)
     end
     
     assert_raises(ArgumentError, "Unknown key(s): failore") do
       { :failore => "stuff", :funny => "business" }.assert_valid_keys([ :failure, :funny ])
+      { :failore => "stuff", :funny => "business" }.assert_valid_keys(:failure, :funny)
     end
   end