diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 6d802e7f567..79ba773ad36 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -5159,8 +5159,8 @@ class Form
             $dir=$conf->user->dir_output;
             if (! empty($object->photo))
             {
-                if ($imagesize == 'mini') $file=get_exdir($id, 2, 0, 0, $object, 'user').getImageFileNameForSize($object->photo, '_mini');
-                else if ($imagesize == 'small') $file=get_exdir($id, 2, 0, 0, $object, 'user').getImageFileNameForSize($object->photo, '_small');
+                if ((string) $imagesize == 'mini') $file=get_exdir($id, 2, 0, 0, $object, 'user').getImageFileNameForSize($object->photo, '_mini');
+                else if ((string) $imagesize == 'small') $file=get_exdir($id, 2, 0, 0, $object, 'user').getImageFileNameForSize($object->photo, '_small');
                 else $file=get_exdir($id, 2, 0, 0, $object, 'user').$object->photo;
             }
             if (! empty($conf->global->MAIN_OLD_IMAGE_LINKS)) $altfile=$object->id.".jpg";	// For backward compatibility