diff --git a/controller/action/NavActions.class.php b/controller/action/NavActions.class.php
index 434fdc31..772aa772 100644
--- a/controller/action/NavActions.class.php
+++ b/controller/action/NavActions.class.php
@@ -39,7 +39,7 @@ class NavActions extends Actions
   {
     $uri = Request::getRelativeUri();
     Controller::queueToRunAfterResponse(function() use($uri) {
-      Slack::sendErrorIfProd('404 for url ' . $uri);
+      Slack::sendErrorIfProd('404 for url ' . $uri, false);
     });
     Response::setStatus(404);
     return ['page/404'];
diff --git a/lib/tools/Slack.class.php b/lib/tools/Slack.class.php
index 5f54f3d0..dd43e56b 100644
--- a/lib/tools/Slack.class.php
+++ b/lib/tools/Slack.class.php
@@ -3,7 +3,7 @@
 class Slack
 {
 
-  public static function sendErrorIfProd($e)
+  public static function sendErrorIfProd($e, $alert = true)
   {
     if ($e instanceof Throwable)
     {
@@ -13,7 +13,7 @@ class Slack
     $slackErrorNotificationUrl = Config::get('slack_error_notification_url');
     if ($slackErrorNotificationUrl)
     {
-      Curl::post($slackErrorNotificationUrl, ['text' => '<!channel> ' . Request::getRelativeUri() . "\n" . $e], ['json_data' => true]);
+      Curl::post($slackErrorNotificationUrl, ['text' => ($alert ? '<!channel> ' : '') . Request::getRelativeUri() . "\n" . $e], ['json_data' => true]);
     }
   }
 }