diff --git a/activesupport/lib/active_support/xml_mini.rb b/activesupport/lib/active_support/xml_mini.rb
index a1728ab955d71a73b3b517eabc56396808532e8c..cddfcddb5733cb0e3b1ad360ef76800bc7253be6 100644
--- a/activesupport/lib/active_support/xml_mini.rb
+++ b/activesupport/lib/active_support/xml_mini.rb
@@ -126,14 +126,10 @@ def to_tag(key, value, options)
     end
 
     def rename_key(key, options = {})
-      camelize  = options.has_key?(:camelize) && options[:camelize]
+      camelize  = options[:camelize]
       dasherize = !options.has_key?(:dasherize) || options[:dasherize]
       if camelize
-        if options[:camelize] == :lower
-          key = key.camelize(:lower)
-        else
-          key = key.camelize
-        end
+        key = true == camelize ? key.camelize : key.camelize(camelize)
       end
       key = _dasherize(key) if dasherize
       key
diff --git a/activesupport/test/test_xml_mini.rb b/activesupport/test/test_xml_mini.rb
index b14a3e154663963d62d8aebad31dc25b5a09765f..309fa234bfd48cd4e9528d37a207b489d55acfa8 100644
--- a/activesupport/test/test_xml_mini.rb
+++ b/activesupport/test/test_xml_mini.rb
@@ -14,6 +14,14 @@ def test_rename_key_does_nothing_with_dasherize_false
     assert_equal "my_key", ActiveSupport::XmlMini.rename_key("my_key", :dasherize => false)
   end
 
+  def test_rename_key_camelizes_with_camelize_false
+    assert_equal "my_key", ActiveSupport::XmlMini.rename_key("my_key", :camelize => false)
+  end
+
+  def test_rename_key_camelizes_with_camelize_nil
+    assert_equal "my_key", ActiveSupport::XmlMini.rename_key("my_key", :camelize => nil)
+  end
+
   def test_rename_key_camelizes_with_camelize_true
     assert_equal "MyKey", ActiveSupport::XmlMini.rename_key("my_key", :camelize => true)
   end
@@ -22,6 +30,10 @@ def test_rename_key_lower_camelizes_with_camelize_lower
     assert_equal "myKey", ActiveSupport::XmlMini.rename_key("my_key", :camelize => :lower)
   end
 
+  def test_rename_key_lower_camelizes_with_camelize_upper
+    assert_equal "MyKey", ActiveSupport::XmlMini.rename_key("my_key", :camelize => :upper)
+  end
+
   def test_rename_key_does_not_dasherize_leading_underscores
     assert_equal "_id", ActiveSupport::XmlMini.rename_key("_id")
   end