diff --git a/lib/delayed/yaml_ext.rb b/lib/delayed/yaml_ext.rb
index 1830c22ce..b58914935 100644
--- a/lib/delayed/yaml_ext.rb
+++ b/lib/delayed/yaml_ext.rb
@@ -2,6 +2,7 @@
 # Classes, Modules and Structs
 
 require 'yaml'
+YAML::ENGINE.yamler = "syck"
 
 class Module
   yaml_as "tag:ruby.yaml.org,2002:module"