diff --git a/include/functions_images.inc.php b/include/functions_images.inc.php
index d309637a4..233d2d3a7 100644
--- a/include/functions_images.inc.php
+++ b/include/functions_images.inc.php
@@ -371,7 +371,7 @@ function serendipity_deleteImage($id) {
     }
 
     if (!is_array($files)) {
-        $messages .= sprintf('<span class="msg_error"><span class="icon-attention-circled" aria-hidden="true"></span> ' . FILE_NOT_FOUND . "</span>\n", $id);
+        $messages .= sprintf('<span class="msg_error"><span class="icon-attention-circled" aria-hidden="true"></span> ' . FILE_NOT_FOUND . "</span>\n", "<b>$id</b>");
         //return false;
     } else {
         foreach ($files AS $file) {
@@ -450,7 +450,7 @@ function serendipity_deleteImageVariations($id) {
     }
 
     if (!is_array($files)) {
-        $messages .= sprintf('<span class="msg_error"><span class="icon-attention-circled" aria-hidden="true"></span> ' . FILE_NOT_FOUND . "</span>\n", $id);
+        $messages .= sprintf('<span class="msg_error"><span class="icon-attention-circled" aria-hidden="true"></span> ' . FILE_NOT_FOUND . "</span>\n", "<b>$id</b>");
         //return false;
     } else {
         foreach ($files AS $file) {