diff --git a/actionpack/lib/action_view/helpers/number_helper.rb b/actionpack/lib/action_view/helpers/number_helper.rb
index d44e6d04963000b1c02fe095fb4eca65fa9d2246..2011351bd26b00bb0693b39ac71e7361ff7ec652 100644
--- a/actionpack/lib/action_view/helpers/number_helper.rb
+++ b/actionpack/lib/action_view/helpers/number_helper.rb
@@ -233,7 +233,7 @@ def number_with_delimiter(number, options = {})
 
         parts = number.to_s.to_str.split('.')
         parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{options[:delimiter]}")
-        parts.join(options[:separator]).html_safe
+        safe_join(parts, options[:separator])
       end
 
       # Formats a +number+ with the specified level of <tt>:precision</tt> (e.g., 112.32 has a precision