1 files changed, 2 insertions, 3 deletions
diff --git a/lib/mail_handler/backends/mail_extensions.rb b/lib/mail_handler/backends/mail_extensions.rb
index f756abd1a..83dce5733 100644
--- a/lib/mail_handler/backends/mail_extensions.rb
+++ b/lib/mail_handler/backends/mail_extensions.rb
@@ -50,8 +50,7 @@ module Mail
 
     # A patched version of the parameter hash that handles nil values without throwing
     # an error.
-    class ParameterHash < IndifferentHash
-
+    class ParameterHash < HashWithIndifferentAccess
         def encoded
           map.sort { |a,b| a.first.to_s <=> b.first.to_s }.map do |key_name, value|
             # The replacement of this commented out line is the change
@@ -64,4 +63,4 @@ module Mail
           end.join(";\r\n\s")
         end
     end
-end
-\ No newline at end of file
+end