diff --git a/package/qos-scripts/files/usr/lib/qos/generate.sh b/package/qos-scripts/files/usr/lib/qos/generate.sh
index 94c01d4619..4ee29ca1e0 100755
--- a/package/qos-scripts/files/usr/lib/qos/generate.sh
+++ b/package/qos-scripts/files/usr/lib/qos/generate.sh
@@ -401,11 +401,11 @@ start_cg() {
 		append up "iptables -t mangle -A OUTPUT -o $device -j ${cg}" "$N"
 		append up "iptables -t mangle -A FORWARD -o $device -j ${cg}" "$N"
 		[ -z "$dl" ] || {
+			append down "iptables -t mangle -A POSTROUTING -o $device -j ${cg}" "$N"
 			[ -z "$halfduplex" ] || {
 				append down "iptables -t mangle -A POSTROUTING -o $device -j IMQ --todev $imqdev" "$N"
 			}
 			append down "iptables -t mangle -A PREROUTING -i $device -j ${cg}" "$N"
-			append down "iptables -t mangle -A POSTROUTING -o $device -j ${cg}" "$N"
 			append down "iptables -t mangle -A PREROUTING -i $device -j IMQ --todev $imqdev" "$N"
 		}
 	done