diff --git a/theme/classic.html b/theme/classic.html
index a31d4dc..7b18366 100644
--- a/theme/classic.html
+++ b/theme/classic.html
@@ -655,9 +655,7 @@
                     files[$i].parentNode.parentNode.innerHTML='<td colspan="3"><img src="'+url+'" alt="'+str+'" onload="if (this.offsetWidth>document.getElementById(\'list-div\').offsetWidth) this.style.width=\'100%\';"></td>';
                     $i--;
                 } else {
-                    var nurl=window.location.href;
-                    if (nurl.substr(-1)!="/") nurl+="/";
-                    var url=nurl+str+'?thumbnails';
+                    var url=files[$i].href.replace(/preview/, 'thumbnails');
                     get_thumbnails_url(url, str, files[$i]);
                 }
             }