diff --git a/is-development.js b/is-development.js
index b8644f52..f198d538 100644
--- a/is-development.js
+++ b/is-development.js
@@ -1,7 +1,7 @@
 module.exports = function isDevelopment (url) {
   return (
     /^wss?:\/\/localhost/.test(url) ||
-    /^wss?:\/\/127\.0\.0\.1/.test(url) ||
+    /^wss?:\/\/127(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}/.test(url) ||
     /^wss?:\/\/ip6-localhost/.test(url) ||
     /^wss?:\/\/::1/.test(url) ||
     /^wss?:\/\/[^/\s:]+\.dev(\/|:|$)/.test(url) ||
diff --git a/test/is-development.test.js b/test/is-development.test.js
index 4038d710..25c6a0e8 100644
--- a/test/is-development.test.js
+++ b/test/is-development.test.js
@@ -10,6 +10,7 @@ function detects (base) {
 it('detects localhost', function () {
   detects('localhost')
   detects('127.0.0.1')
+  detects('127.255.127.1')
 })
 
 it('detects IP6 localhost', function () {