diff --git a/lib/validate.js b/lib/validate.js
index a95d708f..06a72a81 100644
--- a/lib/validate.js
+++ b/lib/validate.js
@@ -72,11 +72,10 @@ addMethod(string, 'ws', function (schemas, msg = 'invalid websocket') {
     name: 'ws',
     message: msg,
     test: value => {
-      if (!value) return true
+      if (typeof value === 'undefined') return true
       try {
-        // eslint-disable-next-line no-new
-        new URL(value)
-        return true
+        const url = new URL(value)
+        return url.protocol === 'ws:' || url.protocol === 'wss:'
       } catch (e) {
         return false
       }