diff --git a/test/content/support.js b/test/content/support.js
index 7b8710c4e6..52a3d8087c 100644
--- a/test/content/support.js
+++ b/test/content/support.js
@@ -1112,5 +1112,6 @@ async function startHTTPServer(port = null) {
 			await Zotero.Promise.delay(10);
 		}
 	}
-	return { httpd, port };
+	var baseURL = `http://localhost:${port}/`
+	return { httpd, port, baseURL };
 }