diff -up cups-1.6.3/backend/ipp.c.ipp-multifile cups-1.6.3/backend/ipp.c
--- cups-1.6.3/backend/ipp.c.ipp-multifile	2013-08-06 17:17:19.359471503 +0100
+++ cups-1.6.3/backend/ipp.c	2013-08-06 17:19:03.346990727 +0100
@@ -1682,10 +1682,13 @@ main(int  argc,				/* I - Number of comm
 	  ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_NAME,
                        "requesting-user-name", NULL, argv[2]);
 
-        if ((i + 1) >= num_files)
-	  ippAddBoolean(request, IPP_TAG_OPERATION, "last-document", 1);
+	ippAddBoolean(request, IPP_TAG_OPERATION, "last-document",
+        	      (i + 1) >= num_files);
 
-	if (document_format)
+	if (num_files > 1)
+	  ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_MIMETYPE,
+		       "document-format", NULL, "application/octet-stream");
+	else if (document_format)
 	  ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_MIMETYPE,
 		       "document-format", NULL, document_format);