diff --git a/src/rougail/data/rougail.dtd b/src/rougail/data/rougail.dtd
index ecb107e7f..6a8710f07 100644
--- a/src/rougail/data/rougail.dtd
+++ b/src/rougail/data/rougail.dtd
@@ -53,7 +53,7 @@
 <!ATTLIST service disabled (True|False) "False">
 <!ATTLIST service engine (none|creole|jinja2) #IMPLIED>
 <!ATTLIST service target CDATA #IMPLIED>
-<!ATTLIST service type (service|mount) "service">
+<!ATTLIST service type (service|mount|swap) "service">
 
 <!ELEMENT ip (#PCDATA)>
 <!ATTLIST ip iplist CDATA #IMPLIED>