diff --git a/src/StringHelper.php b/src/StringHelper.php
index dfc43063..e9f97e24 100644
--- a/src/StringHelper.php
+++ b/src/StringHelper.php
@@ -539,11 +539,11 @@ public static function strspn($str, $mask, $start = null, $length = null)
     {
         $mask = preg_replace('!([\\\\\\-\\]\\[/^])!', '\\\${1}', $mask);
 
-        if ($start && $length) {
+        if ($start !== null && $length !== null) {
             $str = mb_substr($str, $start, $length);
-        } elseif ($start) {
+        } elseif ($start !== null) {
             $str = mb_substr($str, $start);
-        } elseif ($length) {
+        } elseif ($length !== null) {
             trigger_error('\Joomla\String\StringHelper::strspn(): Passing null to parameter #3 ($start) of type int is deprecated', E_USER_DEPRECATED);
             $str = mb_substr($str, 0, $length);
         }