diff --git a/vo_models/vosi/capabilities/models.py b/vo_models/vosi/capabilities/models.py
index fdd0cc8..936c586 100644
--- a/vo_models/vosi/capabilities/models.py
+++ b/vo_models/vosi/capabilities/models.py
@@ -12,6 +12,7 @@
     "vosi": "http://www.ivoa.net/xml/VOSICapabilities/v1.0",
     "xsd": "http://www.w3.org/2001/XMLSchema",
     "xsi": "http://www.w3.org/2001/XMLSchema-instance",
+    "vs": "http://www.ivoa.net/xml/VODataService/v1.1",
 } | VORESOURCE_NSMAP