diff --git a/lib/url.js b/lib/url.js
index 45155fee936bbf..3628f1dcfb9737 100644
--- a/lib/url.js
+++ b/lib/url.js
@@ -50,8 +50,8 @@ const autoEscape = ['\''].concat(unwise);
 const nonHostChars = ['%', '/', '?', ';', '#'].concat(autoEscape);
 const hostEndingChars = ['/', '?', '#'];
 const hostnameMaxLen = 255;
-const hostnamePartPattern = /^[+a-z0-9A-Z_-]{0,63}$/;
-const hostnamePartStart = /^([+a-z0-9A-Z_-]{0,63})(.*)$/;
+const hostnamePartPattern = /^[+a-z0-9A-Z_-]{1,63}$/;
+const hostnamePartStart = /^([+a-z0-9A-Z_-]{1,63})(.*)$/;
 // protocols that can allow "unsafe" and "unwise" chars.
 const unsafeProtocol = {
   'javascript': true,