diff --git a/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDExporter.java b/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDExporter.java
index a5ad456d..c473689f 100644
--- a/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDExporter.java
+++ b/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDExporter.java
@@ -322,8 +322,11 @@ public class ZUGFeRDExporter implements Closeable {
 				"Invoice metadata conforming to ZUGFeRD standard (http://www.ferd-net.de/front_content.php?idcat=231&lang=4)",
 				"text/xml", xmlProvider.getXML());
 
-		if (ZFVersion>1) {
-			// Also attach a ZF1 file for backward compatibility
+		if ((ZFVersion>1)&&(trans!=null)) {
+			/*
+			 *  Also attach a ZF1 file for backward compatibility, but only in case
+			 *  if we do not e.g. embed custom XML (in which case, if its v2, the v1 provider won't be able to deliver data)
+			 */
 			setZUGFeRDVersion(1);
 			xmlProvider.generateXML(trans);
 			filename = getFilenameForVersion(ZFVersion);
@@ -331,6 +334,7 @@ public class ZUGFeRDExporter implements Closeable {
 					"Invoice metadata conforming to ZUGFeRD standard (http://www.ferd-net.de/front_content.php?idcat=231&lang=4)",
 					"text/xml", xmlProvider.getXML());
 			
+			
 		}
 	}