diff --git a/modules/luci-mod-status/htdocs/luci-static/resources/view/status/routes.js b/modules/luci-mod-status/htdocs/luci-static/resources/view/status/routes.js
index 8d7e36f701..dfe19fc70a 100644
--- a/modules/luci-mod-status/htdocs/luci-static/resources/view/status/routes.js
+++ b/modules/luci-mod-status/htdocs/luci-static/resources/view/status/routes.js
@@ -13,13 +13,15 @@ var callNetworkInterfaceDump = rpc.declare({
 
 function applyMask(addr, mask, v6) {
 	var words = v6 ? validation.parseIPv6(addr) : validation.parseIPv4(addr);
+	var bword = v6 ? 0xffff : 0xff;
+	var bwlen = v6 ? 16 : 8;
 
 	if (!words || mask < 0 || mask > (v6 ? 128 : 32))
 		return null;
 
 	for (var i = 0; i < words.length; i++) {
-		var b = Math.min(mask, v6 ? 16 : 8);
-		words[i] &= ((1 << b) - 1);
+		var b = Math.min(mask, bwlen);
+		words[i] &= (bword << (bwlen - b)) & bword;
 		mask -= b;
 	}