diff --git a/ajax/showcomic.php b/ajax/showcomic.php
index 26aea1a..fcb4822 100644
--- a/ajax/showcomic.php
+++ b/ajax/showcomic.php
@@ -69,7 +69,7 @@ if ( $extracted ) {
          //$myext = substr($imgname, -3);
          if ( ! isset(pathinfo($imgname)['extension']) ) continue;
          $myext = strtolower(pathinfo($imgname)['extension']);
-         if ( ($myext == "jpeg") || ($myext == "jpg") || ($myext == "png") || ($myext == "webp") ) {
+         if ( in_array($myext, VALIDIMAGETYPES) ) {
             $imgname = str_replace("#", "", $imgname);
             $imgcontents = $zip->getFromIndex($i);
             $written = file_put_contents($comicoutputfull . $imgname, $imgcontents);
@@ -84,7 +84,7 @@ if ( $extracted ) {
          $entry->extract(false, $comicoutputfull . $outfile);
          if ( ! isset(pathinfo($outfile)['extension']) ) continue;
          $myext = strtolower(pathinfo($outfile)['extension']);
-         if ( ($myext == "jpeg") || ($myext == "jpg") || ($myext == "png") || ($myext == "webp") ) {
+         if ( in_array($myext, VALIDIMAGETYPES) ) {
             $files[] = basename($outfile);
          }
       }
diff --git a/config-dist.php b/config-dist.php
index 6f479d4..3bea0fd 100644
--- a/config-dist.php
+++ b/config-dist.php
@@ -43,3 +43,4 @@ define('DBNAME', 'comics');
 define('SORTBYNAME', "Name");
 define('SORTBYDATE', "Date");
 define('SORTBYREAD', "Read");
+define('VALIDIMAGETYPES', array("jpg", "jpeg", "gif", "png", "webp"));
diff --git a/functions.php b/functions.php
index 121fc87..1f45cc1 100644
--- a/functions.php
+++ b/functions.php
@@ -14,6 +14,11 @@ function getAdultComics() {
    return $adultcomics;
 }
 
+function safeFileName($file = "") {
+   $to_remove = array("<", ">", "#", "\"", "/", "\\", "*", "?", "|");
+   return str_replace($to_remove, '', $file);
+}
+
 function makeThumb($item = "") {
    if ( $item == "" ) { return false; }
    $prefix = (substr(getcwd(), -4) == "ajax") ? "../" : "";
@@ -57,11 +62,7 @@ function makeThumb($item = "") {
          $parts = pathinfo($imgname);
          if ( isset($parts['extension']) ) {
             $imgext = strtolower($parts['extension']);
-            if ( (strcmp($lowest, $imgname) > 0)
-                 && ((strcasecmp($imgext, "jpg") == 0)
-                     || (strcasecmp($imgext, "jpeg") == 0)
-                     || (strcasecmp($imgext, "png") == 0)
-                     || (strcasecmp($imgext, "webp") == 0)) ) {
+            if ( (strcmp($lowest, $imgname) > 0) && in_array($imgext, VALIDIMAGETYPES) ) {
                $lowest = $imgname;
                $imgdata = $zip->getFromIndex($i);
             }
@@ -81,11 +82,7 @@ function makeThumb($item = "") {
          $parts = pathinfo($imgname);
          if ( isset($parts['extension']) ) {
             $imgext = strtolower($parts['extension']);
-            if ( (strcmp($lowest, $imgname) > 0)
-                 && ((strcasecmp($imgext, "jpg") == 0)
-                     || (strcasecmp($imgext, "jpeg") == 0)
-                     || (strcasecmp($imgext, "png") == 0)
-                     || (strcasecmp($imgext, "webp") == 0)) ) {
+            if ( (strcmp($lowest, $imgname) > 0) && in_array($imgext, VALIDIMAGETYPES) ) {
                $lowest = $imgname;
                $didwrite = $entry->extract(false, $outfile);
                if ( !$didwrite ) { return false; }