diff --git a/libs/sysplugins/smarty_resource_custom.php b/libs/sysplugins/smarty_resource_custom.php
index d2a945aa..191fa7c9 100644
--- a/libs/sysplugins/smarty_resource_custom.php
+++ b/libs/sysplugins/smarty_resource_custom.php
@@ -47,7 +47,7 @@ abstract class Smarty_Resource_Custom extends Smarty_Resource
      */
     public function populate(Smarty_Template_Source $source, Smarty_Internal_Template $_template = null)
     {
-        $source->filepath = $source->type . ':' . substr(preg_replace('/[^A-Za-z0-9._]/', '', $source->name), 0, 127);
+        $source->filepath = $source->type . ':' . $this->generateSafeName($source->name);
         $source->uid = sha1($source->type . ':' . $source->name);
         $mtime = $this->fetchTimestamp($source->name);
         if ($mtime !== null) {
@@ -88,6 +88,17 @@ abstract class Smarty_Resource_Custom extends Smarty_Resource
      */
     public function getBasename(Smarty_Template_Source $source)
     {
-        return basename(substr(preg_replace('/[^A-Za-z0-9._]/', '', $source->name), 0, 127));
+        return basename($this->generateSafeName($source->name));
+    }
+
+    /**
+     * Removes special characters from $name and limits its length to 127 characters.
+     *
+     * @param $name
+     *
+     * @return string
+     */
+    private function generateSafeName($name): string {
+        return substr(preg_replace('/[^A-Za-z0-9._]/', '', (string) $name), 0, 127);
     }
 }