lib/usable/mod_extender.rb in usable-3.2.0 vs lib/usable/mod_extender.rb in usable-3.3.0

@@ -24,10 +24,10 @@
       if copy.name.nil?
         const_name = "#{mod_name}Used"
         target.send :remove_const, const_name if target.const_defined? const_name, false
         target.const_set const_name, copy
       end
-      target.usables.add_module copy
+      target.usables.add_module copy if target.respond_to?(:usables)
       target.send options[:method], copy
     end
 
     def mod_name
       if name