diff --git a/monitoring/check_visio_certificate.sh b/monitoring/check_visio_certificate.sh
index 76f57a7..3114186 100755
--- a/monitoring/check_visio_certificate.sh
+++ b/monitoring/check_visio_certificate.sh
@@ -17,7 +17,7 @@ usage() {
     echo
 }
 
-optstring=":hi:C:"
+optstring=":hi:t:"
 while getopts ${optstring} arg; do
 	case ${arg} in
     	h)