diff --git a/tpl/default/thumbnails.html b/tpl/default/thumbnails.html
index f1939798..5f9bef08 100644
--- a/tpl/default/thumbnails.html
+++ b/tpl/default/thumbnails.html
@@ -38,7 +38,7 @@ <h2 class="window-title">{'Thumbnails update'|t}</h2>
       </div>
     </div>
 
-    <input type="hidden" name="ids" value="{function="implode($ids, ',')"}" />
+    <input type="hidden" name="ids" value="{function="implode(',', $ids)"}" />
   </div>
 </div>
 
diff --git a/tpl/vintage/thumbnails.html b/tpl/vintage/thumbnails.html
index 79aebf8d..5cad845b 100644
--- a/tpl/vintage/thumbnails.html
+++ b/tpl/vintage/thumbnails.html
@@ -20,7 +20,7 @@
   </div>
 </div>
 
-<input type="hidden" name="ids" value="{function="implode($ids, ',')"}" />
+<input type="hidden" name="ids" value="{function="implode(',', $ids)"}" />
 
 {include="page.footer"}
 <script src="js/thumbnails_update.min.js?v={$version_hash}"></script>