diff --git a/lib/active_support/cache/mongo_store.rb b/lib/active_support/cache/mongo_store.rb
index 82eb7f6..ad494d5 100644
--- a/lib/active_support/cache/mongo_store.rb
+++ b/lib/active_support/cache/mongo_store.rb
@@ -169,9 +169,14 @@ def clear
       end
       
       private
+
       def mongomapper?
         Kernel.const_defined?(:MongoMapper) && MongoMapper.respond_to?(:database) && MongoMapper.database
       end
+
+      def mongoid?
+        Kernel.const_defined?(:Mongoid) && Mongoid.respond_to?(:database) && Mongoid.database
+      end
       
       def make_collection
         db = case options[:db]
@@ -180,6 +185,8 @@ def make_collection
         else
           if mongomapper?
             MongoMapper.database
+          elsif mongoid?
+            Mongoid.database
           else
             Mongo::DB.new(options[:db_name], Mongo::Connection.new)
           end
@@ -191,4 +198,4 @@ def make_collection
         
     end
   end
-end
\ No newline at end of file
+end