diff --git a/ajax/showcomic.php b/ajax/showcomic.php
index 992567d..184d43e 100644
--- a/ajax/showcomic.php
+++ b/ajax/showcomic.php
@@ -60,7 +60,7 @@ if ( $ext == "cbz" ) {
       $myfile = $comicoutputfull . $file;
       $mynewfile = $comicoutputfull . str_replace("#", "", $file);
       //$myext = strtolower(substr($file, -3));
-      $myext = strtolower(pathinfo($imgname)['extension']);
+      $myext = strtolower(pathinfo($myfile)['extension']);
       if ( ($myext == "jpg") || ($myext == "png") || ($myext == "webp") ) {
          rename($myfile, $mynewfile);
          $files[] = basename($mynewfile);