diff --git a/rules/Php81/Rector/FuncCall/NullToStrictStringFuncCallArgRector.php b/rules/Php81/Rector/FuncCall/NullToStrictStringFuncCallArgRector.php
index d0de7932443..4d7e4d3e011 100644
--- a/rules/Php81/Rector/FuncCall/NullToStrictStringFuncCallArgRector.php
+++ b/rules/Php81/Rector/FuncCall/NullToStrictStringFuncCallArgRector.php
@@ -40,12 +40,20 @@ final class NullToStrictStringFuncCallArgRector extends AbstractRector implement
      * @var array<string, string[]>
      */
     private const ARG_POSITION_NAME_NULL_TO_STRICT_STRING = [
-        'preg_split' => ['subject'],
-        'preg_match' => ['subject'],
-        'preg_match_all' => ['subject'],
-        'explode' => ['string'],
-        'strlen' => ['string'],
-        'str_contains' => ['haystack', 'needle'],
+      'preg_split' => ['subject'], 
+      'preg_match' => ['subject'], 
+      'preg_match_all' => ['subject'], 
+      'explode' => ['string'], 
+      'strlen' => ['string'], 
+      'str_contains' => ['haystack', 'needle'], 
+      'strtotime' => ['datetime'], 
+      'str_replace' => ['subject'], 
+      'substr' => ['string'], 
+      'str_starts_with' => ['haystack', 'needle'], 
+      'strtoupper' => ['string'], 
+      'strtolower' => ['string'], 
+      'strpos' => ['haystack', 'needle'], 
+      'stripos' => ['haystack', 'needle'],
     ];
 
     public function __construct(