diff --git a/de.systopia.civiproxy/CRM/Civiproxy/Mailer.php b/de.systopia.civiproxy/CRM/Civiproxy/Mailer.php
index bdff057..6c37379 100644
--- a/de.systopia.civiproxy/CRM/Civiproxy/Mailer.php
+++ b/de.systopia.civiproxy/CRM/Civiproxy/Mailer.php
@@ -53,7 +53,9 @@ class CRM_Civiproxy_Mailer {
     $proxy_base  = CRM_Core_BAO_Setting::getItem('CiviProxy Settings', 'proxy_url');
 
     // General external functions
+    $value = preg_replace("#{$system_base}civicrm/mailing/url#i",  $proxy_base.'/url.php',         $value);
     $value = preg_replace("#{$system_base}sites/all/modules/civicrm/extern/url.php#i",  $proxy_base.'/url.php',         $value);
+    $value = preg_replace("#{$system_base}civicrm/mailing/open#i", $proxy_base.'/open.php',        $value);
     $value = preg_replace("#{$system_base}sites/all/modules/civicrm/extern/open.php#i", $proxy_base.'/open.php',        $value);
     $value = preg_replace("#{$system_base}sites/default/files/civicrm/persist/#i",      $proxy_base.'/file.php?id=',    $value);
     $value = preg_replace("#{$system_base}civicrm/mosaico/img\?src=#i",                 $proxy_base.'/mosaico.php?id=', $value);
diff --git a/proxy/config.dist.php b/proxy/config.dist.php
index 59510bb..631facd 100644
--- a/proxy/config.dist.php
+++ b/proxy/config.dist.php
@@ -33,11 +33,16 @@ $target_civicrm = 'https://your.civicrm.installation.org';
 
 // default paths, override if you want. Set to NULL to disable
 $target_rest      = $target_civicrm . '/sites/all/modules/civicrm/extern/rest.php';
-$target_url       = $target_civicrm . '/sites/all/modules/civicrm/extern/url.php';
-$target_open      = $target_civicrm . '/sites/all/modules/civicrm/extern/open.php';
 $target_file      = $target_civicrm . '/sites/default/files/civicrm/persist/';
 $target_mosaico   = NULL; // (disabled by default): $target_civicrm . '/civicrm/mosaico/img?src=';
 $target_mail_view = $target_civicrm . '/civicrm/mailing/view';
+$target_url       = $target_civicrm . '/civicrm/mailing/url';
+$target_open      = $target_civicrm . '/civicrm/mailing/open';
+
+// CAUTION: use the following for CiviCRM < 5.27
+$target_url       = $target_civicrm . '/sites/all/modules/civicrm/extern/url.php';
+$target_open      = $target_civicrm . '/sites/all/modules/civicrm/extern/open.php';
+
 
 /****************************************************************
  **                    GENERAL OPTIONS                         **
@@ -155,4 +160,4 @@ $_webhook2api = [
             "parameter_sanitation" => [],
         ]
     ]
-];
\ No newline at end of file
+];