diff --git a/spec/xml_checks_spec.rb b/spec/xml_checks_spec.rb
index b927984a..a50503b4 100644
--- a/spec/xml_checks_spec.rb
+++ b/spec/xml_checks_spec.rb
@@ -33,7 +33,7 @@ describe 'XSD checks' do
     end
 
     unless errors.empty?
-      fail errors.join('\n')
+      fail errors.join("\n")
     end
   end