diff --git a/luci-app-openmptcprouter/luasrc/controller/openmptcprouter.lua b/luci-app-openmptcprouter/luasrc/controller/openmptcprouter.lua
index 4d7ef7c54..5b0d8d527 100644
--- a/luci-app-openmptcprouter/luasrc/controller/openmptcprouter.lua
+++ b/luci-app-openmptcprouter/luasrc/controller/openmptcprouter.lua
@@ -1092,9 +1092,11 @@ function interfaces_status()
 		    end
 	    end
 	    
-	    local mtu = ut.trim(sys.exec("cat /sys/class/net/" .. ifname .. "/mtu | tr -d '\n'"))
-	    if mtu == "" and ifname ~= nil then
-		    mtu = uci:get("openmptcprouter",interface,"mtu") or ""
+	    if ifname ~= nil then
+		    local mtu = ut.trim(sys.exec("cat /sys/class/net/" .. ifname .. "/mtu | tr -d '\n'"))
+		    if mtu == "" and ifname ~= nil then
+			    mtu = uci:get("openmptcprouter",interface,"mtu") or ""
+		    end
 	    end
 
 	    local data = {