diff --git a/bootstrap.php b/bootstrap.php
index 8b7ea7eb9e20e2e4e74ee554242ac110afc861ee..f306bb4550b241aa6aaca9dbbd4a71fb18918fd3 100644
--- a/bootstrap.php
+++ b/bootstrap.php
@@ -295,6 +295,12 @@ class Bootstrap {
         if (extension_loaded('iconv'))
             iconv_set_encoding('internal_encoding', 'UTF-8');
 
+        if (intval(phpversion()) < 7) {
+            function random_int($a, $b) {
+                return rand($a, $b);
+            }
+        }
+
         function mb_str_wc($str) {
             return count(preg_split('~[^\p{L}\p{N}\'].+~u', trim($str)));
         }