lib/json/add/core.rb in json-1.1.3 vs lib/json/add/core.rb in json-1.1.4

@@ -94,10 +94,10 @@
     new(*object['v'])
   end
 
   def to_json(*args)
     klass = self.class.name
-    klass.empty? and raise JSON::JSONError, "Only named structs are supported!"
+    klass.to_s.empty? and raise JSON::JSONError, "Only named structs are supported!"
     {
       'json_class' => klass,
       'v'     => values,
     }.to_json(*args)
   end