diff --git a/lib/netsuite/actions/add.rb b/lib/netsuite/actions/add.rb
index 4cc352661..8acc99e86 100644
--- a/lib/netsuite/actions/add.rb
+++ b/lib/netsuite/actions/add.rb
@@ -49,7 +49,11 @@ def success?
       end
 
       def response_body
-        @response_body ||= response_hash[:base_ref]
+        @response_body ||= if response_hash[:base_ref].is_a?(Nori::StringIOFile)
+          { :@internal_id => Nokogiri::XML(@response.to_s).remove_namespaces!.at_xpath('//baseRef')[:internalId] }
+        else
+          response_hash[:base_ref]
+        end
       end
 
       def response_errors
diff --git a/spec/netsuite/actions/add_spec.rb b/spec/netsuite/actions/add_spec.rb
index c55403c28..2be80d272 100644
--- a/spec/netsuite/actions/add_spec.rb
+++ b/spec/netsuite/actions/add_spec.rb
@@ -114,4 +114,40 @@
     end
   end
 
+  context 'File' do
+    let(:file) do
+      NetSuite::Records::File.new(name: 'foo.pdf', content: 'abc123')
+    end
+
+    context 'when successful' do
+      before do
+        savon.expects(:add).with(:message => {
+          'platformMsgs:record' => {
+            :content! => {
+              'fileCabinet:name' => 'foo.pdf',
+              'fileCabinet:content' => 'abc123',
+            },
+            '@xsi:type' => 'fileCabinet:File'
+          },
+        }).returns(File.read('spec/support/fixtures/add/add_file.xml'))
+      end
+
+      it 'makes a valid request to the NetSuite API' do
+        NetSuite::Actions::Add.call([file])
+      end
+
+      it 'returns a valid Response object' do
+        response = NetSuite::Actions::Add.call([file])
+        expect(response).to be_kind_of(NetSuite::Response)
+        expect(response).to be_success
+      end
+
+      it 'properly extracts internal ID from response' do
+        file.add
+
+        expect(file.internal_id).to eq('23556')
+      end
+    end
+  end
+
 end
diff --git a/spec/support/fixtures/add/add_file.xml b/spec/support/fixtures/add/add_file.xml
new file mode 100644
index 000000000..99c9962b5
--- /dev/null
+++ b/spec/support/fixtures/add/add_file.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <soapenv:Header>
+    <platformMsgs:documentInfo xmlns:platformMsgs="urn:messages_2020_2.platform.webservices.netsuite.com">
+      <platformMsgs:nsId>REDACTED</platformMsgs:nsId>
+    </platformMsgs:documentInfo>
+  </soapenv:Header>
+  <soapenv:Body>
+    <addResponse xmlns="urn:messages_2020_2.platform.webservices.netsuite.com">
+      <writeResponse>
+        <platformCore:status xmlns:platformCore="urn:core_2020_2.platform.webservices.netsuite.com" isSuccess="true">
+          <platformCore:statusDetail>
+            <platformCore:afterSubmitFailed>false</platformCore:afterSubmitFailed>
+          </platformCore:statusDetail>
+        </platformCore:status>
+        <baseRef xmlns:platformCore="urn:core_2020_2.platform.webservices.netsuite.com" internalId="23556" type="file" xsi:type="platformCore:RecordRef"/>
+      </writeResponse>
+    </addResponse>
+  </soapenv:Body>
+</soapenv:Envelope>