diff --git a/package/network/services/dnsmasq/files/dnsmasq.init b/package/network/services/dnsmasq/files/dnsmasq.init
index e811a20d1fa..cce7558fc97 100644
--- a/package/network/services/dnsmasq/files/dnsmasq.init
+++ b/package/network/services/dnsmasq/files/dnsmasq.init
@@ -526,7 +526,8 @@ dhcp_relay_add() {
 	if [ -z "$interface" ]; then
 		xappend "--dhcp-relay=$local_addr,$server_addr"
 	else
-		xappend "--dhcp-relay=$local_addr,$server_addr,$interface"
+		network_get_device ifname "$interface" || return
+		xappend "--dhcp-relay=$local_addr,$server_addr,$ifname"
 	fi
 }