@@ -686,7 +686,13 @@ static void Initialize(Local<Object> target,
   auto ctor_tmpl = NewFunctionTemplate(isolate, URLPattern::New);
   auto instance_template = ctor_tmpl->InstanceTemplate();
   auto prototype_template = ctor_tmpl->PrototypeTemplate();
-  ctor_tmpl->SetClassName(FIXED_ONE_BYTE_STRING(isolate, "URLPattern"));
+  Local<String> url_pattern_string =
+      FIXED_ONE_BYTE_STRING(isolate, "URLPattern");
+  ctor_tmpl->SetClassName(url_pattern_string);
+  prototype_template->Set(
+      v8::Symbol::GetToStringTag(isolate),
+      url_pattern_string,
+      static_cast<PropertyAttribute>(ReadOnly | v8::DontEnum));
 
   // The signature is used to prevent the property accessors from being
   // called on the wrong receiver object (`this`)
 
@@ -5,6 +5,20 @@ require('../common');
 const assert = require('assert');
 const { URLPattern } = require('url');
 
+{
+  assert.deepStrictEqual(
+    Object.getOwnPropertyDescriptor(URLPattern.prototype, Symbol.toStringTag),
+    {
+      configurable: true,
+      enumerable: false,
+      value: 'URLPattern',
+      writable: false,
+    });
+  assert.strictEqual(
+    Object.prototype.toString.call(new URLPattern()),
+    '[object URLPattern]');
+}
+
 // Verify that if an error is thrown while accessing any of the
 // init options, the error is appropriately propagated.
 assert.throws(() => {