diff --git a/lib/deepl/document_api.rb b/lib/deepl/document_api.rb
index 5416329..738fde9 100644
--- a/lib/deepl/document_api.rb
+++ b/lib/deepl/document_api.rb
@@ -91,7 +91,7 @@ def download(document_handle, output_file)
 
     def translate_document(input_file, output_file, source_lang, target_lang, # rubocop:disable Metrics/MethodLength,Metrics/ParameterLists
                            filename = nil, options = {}, additional_headers = {})
-      raise IOError 'File already exists at output path' if File.exist?(output_file)
+      raise IOError.new('File already exists at output path') if File.exist?(output_file)
 
       begin
         handle = upload(input_file, source_lang, target_lang, filename, options,
diff --git a/spec/integration_tests/document_api_spec.rb b/spec/integration_tests/document_api_spec.rb
index 4773992..17882bb 100644
--- a/spec/integration_tests/document_api_spec.rb
+++ b/spec/integration_tests/document_api_spec.rb
@@ -32,6 +32,19 @@
 
       expect(example_document_translation(target_lang)).to eq(output_file_contents)
     end
+    it 'raises an IOError when the output file already exists' do
+      source_lang = default_lang_args[:source_lang]
+      target_lang = default_lang_args[:target_lang]
+      example_doc_path = example_document_path(source_lang)
+
+      FileUtils.touch(output_document_path)
+
+      expect do
+        DeepL.document.translate_document(example_doc_path, output_document_path,
+          source_lang, target_lang, File.basename(example_doc_path),
+          {})
+      end.to raise_error(IOError)
+    end
 
     it 'Translates a document from a filepath without a filename' do
       File.unlink(output_document_path)