diff --git a/scripts/validate_all_xml.sh b/scripts/validate_all_xml.sh
index d29e582f..32997391 100755
--- a/scripts/validate_all_xml.sh
+++ b/scripts/validate_all_xml.sh
@@ -23,7 +23,7 @@ if [ ! -e $XSD2PGSCHEMA ] ; then
  ./scripts/update_extlibs.sh
 fi
 
-java -classpath $XSD2PGSCHEMA xmlvalidator --xsd $PDBX_VALIDATION_XSD --xml $XML_DIR
+java -classpath $XSD2PGSCHEMA xmlvalidator --xsd $PDBX_VALIDATION_XSD --xml $XML_DIR --sync chk_sum_pdbx_valid
 
 if [ $? != 0 ] ; then
  echo "$0 aborted."