diff --git a/src/XmlFileUtil.cpp b/src/XmlFileUtil.cpp
index 8a3561af5c..81b787d122 100644
--- a/src/XmlFileUtil.cpp
+++ b/src/XmlFileUtil.cpp
@@ -619,6 +619,9 @@ void XmlFileUtil::AnnotateXNodeTree( XNode *pNode, const RString &sFile )
 
 		/* Directory of caller, for relative paths: */
 		pNode->AppendAttr( "_Dir", sDir );
+
+		/* Note that this node came from a legacy XML file */
+		pNode->AppendAttr( "_LegacyXml", true );
 	}
 }