diff --git a/qosmngr/files/common/lib/qos/iptables.sh b/qosmngr/files/common/lib/qos/iptables.sh
index 7be8da06d..260f4dbaa 100755
--- a/qosmngr/files/common/lib/qos/iptables.sh
+++ b/qosmngr/files/common/lib/qos/iptables.sh
@@ -198,7 +198,7 @@ handle_iptables_rules() {
     [ -n "$IP_RULE" ] && [ -n "$dscp_mark" ] && append_rule_to_mangle_table "qos_forward" $ip_version
 
     if [ -n "$IP_RULE" ] && [ -n "$traffic_class" ]; then
-	if [ "all_interfaces" == "1" ]; then
+	if [ "$all_interfaces" == "1" ]; then
 	    append_rule_to_mangle_table "qos_output" $ip_version
 	elif [ "$ifname" == "lo" ]; then
             #write iptables rule for putting WAN directed internal packets in different queue