diff --git a/inc/power.inc.sh b/inc/power.inc.sh
index 0f915243..d90a4057 100644
--- a/inc/power.inc.sh
+++ b/inc/power.inc.sh
@@ -910,14 +910,14 @@ PDUCONTROL(){
 			echo
 			if [ "${PORT_SEL}" == "" ]; then
 				sleep 1s
-				unset PORTSEL
+				PORTSEL=""
 				PDUCONTROL
 				exit 0
 			fi
 			;;
 		*)
 			if [ "${PORT_SEL}" == "" ]; then
-				unset PORTSEL
+				PORTSEL=""
 				PDUCONTROL
 				exit 0
 			fi