diff --git a/lib/httparty/parser.rb b/lib/httparty/parser.rb
index 44451ce4..8301b451 100644
--- a/lib/httparty/parser.rb
+++ b/lib/httparty/parser.rb
@@ -119,7 +119,7 @@ def parse
 
     def xml
       require 'multi_xml'
-      MultiXml.parse(body)
+      (defined?(MultiXML) ? MultiXML : MultiXml).parse(body)
     end
 
     UTF8_BOM = "\xEF\xBB\xBF"
diff --git a/spec/httparty/parser_spec.rb b/spec/httparty/parser_spec.rb
index a23597fc..281ae018 100644
--- a/spec/httparty/parser_spec.rb
+++ b/spec/httparty/parser_spec.rb
@@ -165,8 +165,9 @@ def self.name
       HTTParty::Parser.new('body', nil)
     end
 
-    it "parses xml with MultiXml" do
-      expect(MultiXml).to receive(:parse).with('body')
+    it "parses xml with MultiXML" do
+      xml_parser = defined?(MultiXML) ? MultiXML : MultiXml
+      expect(xml_parser).to receive(:parse).with('body')
       subject.send(:xml)
     end