diff --git a/actionpack/lib/action_view/helpers/active_model_helper.rb b/actionpack/lib/action_view/helpers/active_model_helper.rb
index c9231225e1..7cc1e48572 100644
--- a/actionpack/lib/action_view/helpers/active_model_helper.rb
+++ b/actionpack/lib/action_view/helpers/active_model_helper.rb
@@ -6,7 +6,7 @@
 
 module ActionView
   class Base
-    @@field_error_proc = Proc.new{ |html_tag, instance| "<div class=\"fieldWithErrors\">#{html_tag}</div>" }
+    @@field_error_proc = Proc.new{ |html_tag, instance| "<div class=\"fieldWithErrors\">#{html_tag}</div>".html_safe! }
     cattr_accessor :field_error_proc
   end