diff --git a/lib/hashie/extensions/indifferent_access.rb b/lib/hashie/extensions/indifferent_access.rb
index d6b9da33..2ff5f287 100644
--- a/lib/hashie/extensions/indifferent_access.rb
+++ b/lib/hashie/extensions/indifferent_access.rb
@@ -25,6 +25,11 @@ module Extensions
     module IndifferentAccess
       include Hashie::Extensions::RubyVersionCheck
 
+      # @api private
+      def self.convert_key(key)
+        key.to_s
+      end
+
       def self.included(base)
         Hashie::Extensions::Dash::IndifferentAccess.maybe_extend(base)
 
@@ -68,7 +73,7 @@ def self.inject(hash)
       end
 
       def convert_key(key)
-        key.to_s
+        IndifferentAccess.convert_key(key)
       end
 
       # Iterates through the keys and values, reconverting them to