diff --git a/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php b/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php
index 3d6ddc16a28..b04dab0f8a4 100644
--- a/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php
+++ b/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php
@@ -2113,7 +2113,7 @@ public function rule_div($fid, $id, $div = true, $compact = false)
                     'href' => '#',
                     'id' => "ruleadv{$id}",
                     'title' => $adv_title,
-                    'data-onclick' => ['rule_adv_switch', $id, '__THIS__'],
+                    'data-onclick' => ['rule_adv_switch', $id, '__THIS__', ['preventDefault' => true]],
                     'class' => 'show',
                 ],
                     html::span(['class' => 'inner'], $adv_title)
@@ -2140,7 +2140,7 @@ public function rule_div($fid, $id, $div = true, $compact = false)
                     'href' => '#',
                     'id' => "ruleadv{$id}",
                     'title' => $adv_title,
-                    'data-onclick' => ['rule_adv_switch', $id, '__THIS__'],
+                    'data-onclick' => ['rule_adv_switch', $id, '__THIS__', ['preventDefault' => true]],
                     'class' => 'advanced show',
                 ],
                 html::span(['class' => 'inner'], $adv_title)
@@ -2150,7 +2150,7 @@ public function rule_div($fid, $id, $div = true, $compact = false)
                 'href' => '#',
                 'id' => "ruleadd{$id}",
                 'title' => $add_title,
-                'data-onclick' => ['managesieve_ruleadd', $id],
+                'data-onclick' => ['managesieve_ruleadd', $id, ['preventDefault' => true]],
                 'class' => 'button create add',
             ],
             html::span(['class' => 'inner'], $add_title)
@@ -2159,7 +2159,7 @@ public function rule_div($fid, $id, $div = true, $compact = false)
                 'href' => '#',
                 'id' => "ruledel{$id}",
                 'title' => $del_title,
-                'data-onclick' => ['managesieve_ruledel', $id],
+                'data-onclick' => ['managesieve_ruledel', $id, ['preventDefault' => true]],
                 'class' => 'button delete del ' . $rows_num < 2 ? 'disabled' : '',
             ],
             html::span(['class' => 'inner'], $del_title)
diff --git a/plugins/newmail_notifier/newmail_notifier.php b/plugins/newmail_notifier/newmail_notifier.php
index a856cdc455f..a51457e0df6 100644
--- a/plugins/newmail_notifier/newmail_notifier.php
+++ b/plugins/newmail_notifier/newmail_notifier.php
@@ -111,7 +111,7 @@ public function prefs_list($args)
                 $field_id = '_' . $key;
                 $input = new html_checkbox(['name' => $field_id, 'id' => $field_id, 'value' => 1]);
                 $content = $input->show($this->rc->config->get($key))
-                    . ' ' . html::a(['href' => '#', 'data-onclick' => ['newmail_notifier_test_' . $type]],
+                    . ' ' . html::a(['href' => '#', 'data-onclick' => ['newmail_notifier_test_' . $type, ['preventDefault' => true]]],
                         $this->gettext('test'));
 
                 $args['blocks']['new_message']['options'][$key] = [
diff --git a/program/actions/mail/show.php b/program/actions/mail/show.php
index 2692a44b5d6..476756fd2e9 100644
--- a/program/actions/mail/show.php
+++ b/program/actions/mail/show.php
@@ -751,7 +751,7 @@ public static function message_body($attrib)
                         $supported = in_array($mimetype, self::$CLIENT_MIMETYPES);
                         $show_link_attr = [
                             'href' => self::$MESSAGE->get_part_url($attach_prop->mime_id, false),
-                            'data-onclick' => ['command', 'load-attachment', $attach_prop->mime_id, '__THIS__'],
+                            'data-onclick' => ['command', 'load-attachment', $attach_prop->mime_id, '__THIS__', ['preventDefault' => true]],
                         ];
                         $download_link_attr = [
                             'href' => $show_link_attr['href'] . '&_download=1',
diff --git a/program/include/rcmail_output_html.php b/program/include/rcmail_output_html.php
index fd59bb8634e..61ed88a97e8 100644
--- a/program/include/rcmail_output_html.php
+++ b/program/include/rcmail_output_html.php
@@ -2417,7 +2417,7 @@ public function search_form($attrib)
         if (empty($attrib['form']) && empty($attrib['no-form'])) {
             $out = $this->form_tag([
                 'name' => !empty($attrib['form-name']) ? $attrib['form-name'] : 'rcmqsearchform',
-                'data-onsubmit' => ['command', !empty($attrib['command']) ? $attrib['command'] : 'search'],
+                'data-onsubmit' => ['command', !empty($attrib['command']) ? $attrib['command'] : 'search', ['preventDefault' => true]],
                 // 'style'    => "display:inline"
             ], $out);
         }
diff --git a/program/js/app.js b/program/js/app.js
index b204f72c479..7210290e365 100644
--- a/program/js/app.js
+++ b/program/js/app.js
@@ -10849,15 +10849,23 @@ function rcube_webmail() {
             }
             return arg;
         });
+        var preventDefault = false;
+        if (typeof eventArgs.at(-1) === 'object') {
+            options = eventArgs.pop();
+            var preventDefault = Boolean(options.preventDefault);
+        }
         elem.addEventListener(eventName, (ev) => {
             // Inject a reference to the event object, if required.
-            var localEventArgs = eventArgs.map(function (arg) {
+            var localEventArgs = eventArgs.map((arg) => {
                 if (arg === '__EVENT__') {
                     return ev;
                 }
                 return arg;
             });
-            this[methodName](...localEventArgs);
+            if (preventDefault) {
+                ev.preventDefault();
+            }
+            return this[methodName](...localEventArgs);
         });
     };