diff --git a/ChangeLog b/ChangeLog
index f71af24a6d..65756cd3a5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -49,6 +49,7 @@ phpMyAdmin - ChangeLog
 - issue        Fixed url.php crashing because it's not loading the DatabaseInterface service
 - issue #15540 Fixed uncaught TypeError: htmlspecialchars() in NavigationTree
 - issue        Fix twig deprecation notices for php 8.0
+- issue #15435 Fix ReCAPTCHA couldn't find user-provided function: Functions.recaptchaCallback
 
 4.9.3 (not yet released)
 - issue #15570 Fix page contents go underneath of floating menubar in some cases
diff --git a/js/functions.js b/js/functions.js
index 5d6bf74c06..2d7a4fdb00 100644
--- a/js/functions.js
+++ b/js/functions.js
@@ -4914,8 +4914,9 @@ Functions.toggleDatepickerIfInvalid = function ($td, $inputField) {
 
 /**
  * Function to submit the login form after validation is done.
+ * NOTE: do NOT use a module or it will break the callback, issue #15435
  */
-Functions.recaptchaCallback = function () {
+Functions_recaptchaCallback = function () {
     $('#login_form').trigger('submit');
 };
 
diff --git a/templates/login/form.twig b/templates/login/form.twig
index 9fe16f759d..b1dd0e7fbc 100644
--- a/templates/login/form.twig
+++ b/templates/login/form.twig
@@ -76,7 +76,7 @@
   <fieldset class="tblFooters">
     {% if has_captcha %}
       <script src="https://www.google.com/recaptcha/api.js?hl={{ lang }}" async defer></script>
-      <input class="btn btn-primary g-recaptcha" data-sitekey="{{ captcha_key }}" data-callback="Functions.recaptchaCallback" value="{% trans 'Go' %}" type="submit" id="input_go">
+      <input class="btn btn-primary g-recaptcha" data-sitekey="{{ captcha_key }}" data-callback="Functions_recaptchaCallback" value="{% trans 'Go' %}" type="submit" id="input_go">
     {% else %}
       <input class="btn btn-primary" value="{% trans 'Go' %}" type="submit" id="input_go">
     {% endif %}