opal/corelib/runtime.js in opal-1.7.2 vs opal/corelib/runtime.js in opal-1.7.3

@@ -822,9 +822,12 @@
   // the object at `$$meta` for future use, and then returned.
   //
   // @param object [Object] the ruby object
   // @return [Class] the singleton class for object
   Opal.get_singleton_class = function(object) {
+    if (object.$$is_number) {
+      $raise(Opal.TypeError, "can't define singleton");
+    }
     if (object.$$meta) {
       return object.$$meta;
     }
 
     if (object.hasOwnProperty('$$is_class')) {