diff --git a/spec/twiml/voice_response_spec.rb b/spec/twiml/voice_response_spec.rb
index dd1a06cc4..a07899e29 100644
--- a/spec/twiml/voice_response_spec.rb
+++ b/spec/twiml/voice_response_spec.rb
@@ -616,6 +616,40 @@
       expect(doc).to be_equivalent_to(expected_doc).respecting_element_order
     end
 
+    it 'should allow Dial.sip' do
+      expected_doc = parse <<-XML
+        <Response>
+          <Dial>
+            <Sip>foo@example.com</Sip>
+          </Dial>
+        </Response>
+      XML
+      dial = Twilio::TwiML::Dial.new
+      dial.sip(sip_url: 'foo@example.com')
+
+      response = Twilio::TwiML::VoiceResponse.new
+      response.append(dial)
+      doc = parse(response)
+      expect(doc).to be_equivalent_to(expected_doc).respecting_element_order
+    end
+
+    it 'should allow Dial.sip with username, password' do
+      expected_doc = parse <<-XML
+        <Response>
+          <Dial>
+            <Sip username="foo" password="bar">foo@example.com</Sip>
+          </Dial>
+        </Response>
+      XML
+      dial = Twilio::TwiML::Dial.new
+      dial.sip(sip_url: 'foo@example.com', username: 'foo', password: 'bar')
+
+      response = Twilio::TwiML::VoiceResponse.new
+      response.append(dial)
+      doc = parse(response)
+      expect(doc).to be_equivalent_to(expected_doc).respecting_element_order
+    end
+
     it 'should allow Dial.number' do
       expected_doc = parse <<-XML
         <Response>