diff --git a/bin/import_xml.rng b/bin/import_xml.rng
index 0dc844b59df..ab19dcd1df8 100644
--- a/bin/import_xml.rng
+++ b/bin/import_xml.rng
@@ -100,6 +100,7 @@
             <rng:optional><rng:attribute name="menu"/></rng:optional>
             <rng:optional><rng:attribute name="keyword"/></rng:optional>
             <rng:optional><rng:attribute name="rml"/></rng:optional>
+            <rng:optional><rng:attribute name="sxw"/></rng:optional>
             <rng:optional><rng:attribute name="xml"/></rng:optional>
             <rng:optional><rng:attribute name="xsl"/></rng:optional>
             <rng:optional> <rng:attribute name="auto" /> </rng:optional>