MultiJson.default_engine not MultiJson.engine

lib/brakeman/report.rb

@@ -19,7 +19,7 @@ else
 end
 
 #This is so OkJson will work with symbol values
-if MultiJson.engine == MultiJson::Adapters::OkJson
+if MultiJson.default_engine == :ok_json 
   class Symbol
     def to_json
       self.to_s.inspect