diff --git a/zfs/zfs-clean.sh b/zfs/zfs-clean.sh
index 2991e76..234ab09 100644
--- a/zfs/zfs-clean.sh
+++ b/zfs/zfs-clean.sh
@@ -9,7 +9,9 @@ if [ -z "$1" ]; then
     exit 1
 fi
     
-if ! [ -z "$1" ] && [ "$1" == "upgrades" ]; then
+if [ -n "$1" ] && [ "$1" == "upgrades" ]; then
+    shift
+    
     while getopts "r:" opt; do
         case "$opt" in
             r) REGEX=${OPTARG};;