diff --git a/lib/galaxy/tools/xsd/galaxy.xsd b/lib/galaxy/tools/xsd/galaxy.xsd
index d396ac7f659..d2d432ddc6c 100644
--- a/lib/galaxy/tools/xsd/galaxy.xsd
+++ b/lib/galaxy/tools/xsd/galaxy.xsd
@@ -2358,6 +2358,7 @@ allow access to Python code to generate options for a select list. See
       <xs:enumeration value="select"/>
       <xs:enumeration value="data_column"/>
       <xs:enumeration value="hidden"/>
+      <xs:enumeration value="hidden_data"/>
       <xs:enumeration value="baseurl"/>
       <xs:enumeration value="file"/>
       <xs:enumeration value="data"/>