diff --git a/bin/pdd b/bin/pdd
index ead2c3c..f60ad4e 100755
--- a/bin/pdd
+++ b/bin/pdd
@@ -38,6 +38,6 @@ end
 if opts.help?
   puts opts
 else
-  file = opts.file? ? opts[:file] : STDOUT
-  File.write(file, PDD::Base.new(opts).xml)
+  file = opts.file? ? File.new(opts[:file], 'w') : STDOUT
+  file << PDD::Base.new(opts).xml
 end
diff --git a/features/cli.feature b/features/cli.feature
index 7b0d283..d898ded 100644
--- a/features/cli.feature
+++ b/features/cli.feature
@@ -33,6 +33,6 @@ Feature: Command Line Processing
     ~~  and second
     ~~
     """
-    When I run bin/pdd with " "
+    When I run bin/pdd with "> out.xml"
     Then Exit code is zero
-    And Stdout contains "<puzzles>"
+    And XML file "out.xml" matches "/puzzles[count(puzzle)=1]"
diff --git a/features/step_definitions/steps.rb b/features/step_definitions/steps.rb
index 19c0d96..0a9dc0b 100644
--- a/features/step_definitions/steps.rb
+++ b/features/step_definitions/steps.rb
@@ -81,6 +81,7 @@
 end
 
 Then(/^XML file "([^"]+)" matches "([^"]+)"$/) do |file, xpath|
+  fail "File #{file} doesn't exit" unless File.exist?(file)
   xml = Nokogiri::XML.parse(File.read(file))
   if xml.xpath(xpath).empty?
     fail "XML file #{file} doesn't match \"#{xpath}\":\n#{xml}"