diff --git a/run.sh b/run.sh
index 427b838..00d5998 100644
--- a/run.sh
+++ b/run.sh
@@ -10,15 +10,16 @@ if [[ -z "$VLANS" ]];then
 	exit 1
 fi
 # build interface list with parent interface and vlan ids
-ALLVLANIF=$(echo -n $VLANS | sed -re "s/\b([0-9]+)/${INTERFACE}.\1/g")
+ALLVLANIF=$(echo -n "$VLANS" | sed -re "s/\b([0-9]+)/${INTERFACE}.\1/g")
 
 # get MTU of parent interface
 MTU=$(ip link show $INTERFACE | grep -Ei 'mtu \d+' | cut -d " " -f2)
 
 # cleanup non used vlan interfaces
-for VLAN in $(ls -1 /sys/class/net | grep -E "^${INTERFACE}\\." | grep -Ev "$(echo $ALLVLANIF | tr ' ' '|')") ;do
+# shellcheck disable=SC2010
+for VLAN in $(ls -1 /sys/class/net | grep -E "^${INTERFACE}\\." | grep -Ev "$(echo "$ALLVLANIF" | tr ' ' '|')") ;do
 	echo "Deleting orphaned interface: $VLAN"
-	ip link delete $VLAN
+	ip link delete "$VLAN"
 done
 
 # for each vlan id
@@ -27,7 +28,7 @@ for VLAN in $VLANS; do
     # create vlan interface
     [[ ! -d "/sys/class/net/${VLANIF}" ]] && {
         echo "Creating interface ${VLANIF}"
-        ip link add link $INTERFACE name "$VLANIF" mtu $MTU type vlan id $VLAN
+        ip link add link $INTERFACE name "$VLANIF" mtu "$MTU" type vlan id "$VLAN"
     }
     echo "Bring up $VLANIF interface"
     ip link set "$VLANIF" up
@@ -38,9 +39,9 @@ for VLAN in $VLANS; do
         rm "/var/run/udhcpc.${VLANIF}.pid"
     }
     echo "Starting dhcp client on ${VLANIF}"
-    udhcpc -b -i $VLANIF -x hostname:"$HOSTNAME" -p "/var/run/udhcpc.${VLANIF}.pid"
+    udhcpc -b -i "$VLANIF" -x hostname:"$HOSTNAME" -p "/var/run/udhcpc.${VLANIF}.pid"
 done
 
 echo "Starting mDNS repeater process ... "
 # run repeater on vlan interfaces
-exec /bin/mdns-repeater -f $ALLVLANIF
+exec /bin/mdns-repeater -f "$ALLVLANIF"