diff --git a/src/docker.js b/src/docker.js
index 3a09a165f..0ee563753 100644
--- a/src/docker.js
+++ b/src/docker.js
@@ -733,7 +733,8 @@ function validateServerAddress(serverAddress) {
 
     // workaround https://github.com/oncletom/tld.js/issues/73
     const tmp = serverAddress.replace('_', '-');
-    if (!tld.isValidHostname(tmp)) return new BoxError(BoxError.BAD_FIELD, 'serverAddress is not a valid hostname');
+    if (!tld.isValid(tmp)) return new BoxError(BoxError.BAD_FIELD, 'Hostname is not a valid domain name');
+    if (tmp.length > 253) return new BoxError(BoxError.BAD_FIELD, 'Hostname length exceeds 253 characters');
 
     return null;
 }