diff --git a/phpBB/includes/functions_posting.php b/phpBB/includes/functions_posting.php
index d6f7c9bab4..b9b518ad32 100644
--- a/phpBB/includes/functions_posting.php
+++ b/phpBB/includes/functions_posting.php
@@ -425,9 +425,6 @@ function upload_attachment($form_name, $forum_id, $local = false, $local_storage
 	// Whether the uploaded file is in the image category
 	$is_image = (isset($extensions[$file->get('extension')]['display_cat'])) ? $extensions[$file->get('extension')]['display_cat'] == ATTACHMENT_CATEGORY_IMAGE : false;
 
-	// Do we have to create a thumbnail?
-	$filedata['thumbnail'] = ($is_image && $config['img_create_thumbnail']) ? 1 : 0;
-
 	if (!$auth->acl_get('a_') && !$auth->acl_get('m_', $forum_id))
 	{
 		// Check Image Size, if it is an image
@@ -455,6 +452,9 @@ function upload_attachment($form_name, $forum_id, $local = false, $local_storage
 	// Only then perform additional image checks.
 	$file->move_file($config['upload_path'], false, !$is_image);
 
+	// Do we have to create a thumbnail?
+	$filedata['thumbnail'] = ($is_image && $config['img_create_thumbnail']) ? 1 : 0;
+
 	if (sizeof($file->error))
 	{
 		$file->remove();