diff --git a/libs/plugins/function.html_image.php b/libs/plugins/function.html_image.php
index 8c7507b3..e92dfd27 100644
--- a/libs/plugins/function.html_image.php
+++ b/libs/plugins/function.html_image.php
@@ -93,7 +93,7 @@ function smarty_function_html_image($params, &$smarty)
         return;
     }
 
-    if(substr($file,0,1) == DIR_SEP) {
+    if(substr($file,0,1) == DIRECTORY_SEPARATOR) {
         $_image_path = $basedir . $file;
     } else {
         $_image_path = $file;