1 files changed, 2 insertions, 1 deletions
diff --git a/activesupport/lib/active_support/xml_mini/libxmlsax.rb b/activesupport/lib/active_support/xml_mini/libxmlsax.rb
index fe2c1b9349..2536b1f33e 100644
--- a/activesupport/lib/active_support/xml_mini/libxmlsax.rb
+++ b/activesupport/lib/active_support/xml_mini/libxmlsax.rb
@@ -1,5 +1,6 @@
 require 'libxml'
 require 'active_support/core_ext/object/blank'
+require 'stringio'
 
 # = XmlMini LibXML implementation using a SAX-based parser
 module ActiveSupport
@@ -82,4 +83,4 @@ module ActiveSupport
       end
     end
   end
-end
-\ No newline at end of file
+end