diff --git a/bandwidth.gemspec b/bandwidth.gemspec
index 1c78ff97..8c7736c1 100644
--- a/bandwidth.gemspec
+++ b/bandwidth.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name = 'bandwidth-sdk'
-  s.version = '3.13.0'
+  s.version = '3.13.1'
   s.summary = 'bandwidth'
   s.description = 'Bandwidth\'s set of APIs'
   s.authors = ['APIMatic SDK Generator']
diff --git a/lib/bandwidth/voice_lib/bxml/verbs/transfer.rb b/lib/bandwidth/voice_lib/bxml/verbs/transfer.rb
index d4a3c907..680da916 100644
--- a/lib/bandwidth/voice_lib/bxml/verbs/transfer.rb
+++ b/lib/bandwidth/voice_lib/bxml/verbs/transfer.rb
@@ -31,11 +31,15 @@ def embedded_xml(xml, property, type)
               s.to_bxml(xml)
             end
           end
-          phone_numbers.each do |number|
-            embedded_xml(xml, number, PhoneNumber)
+          if not phone_numbers.nil?
+            phone_numbers.each do |number|
+              embedded_xml(xml, number, PhoneNumber)
+            end
           end
-          sip_uris.each do |sip_uri|
-            embedded_xml(xml, sip_uri, SipUri)
+          if not sip_uris.nil?
+            sip_uris.each do |sip_uri|
+              embedded_xml(xml, sip_uri, SipUri)
+            end
           end
         end
       end