diff --git a/composer.json b/composer.json
index 5386520..a9a6a2a 100644
--- a/composer.json
+++ b/composer.json
@@ -37,7 +37,7 @@
         "roave/backward-compatibility-check": "^8.0",
         "testo/bridge-infection": "^0.1.6",
         "testo/testo": "^0.10.25",
-        "vimeo/psalm": "^6.16"
+        "vimeo/psalm": "^7.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/LostDateTimeMutationRector.php b/src/LostDateTimeMutationRector.php
index d295419..89fb2f7 100644
--- a/src/LostDateTimeMutationRector.php
+++ b/src/LostDateTimeMutationRector.php
@@ -396,10 +396,8 @@ private function forgetAssignedVariables(?Expr $expr, Node $context): void
             return;
         }
 
-        foreach ($expr->items as $item) {
-            if ($item !== null) {
-                $this->forgetAssignedVariables($item->value, $context);
-            }
+        foreach (array_filter($expr->items) as $item) {
+            $this->forgetAssignedVariables($item->value, $context);
         }
     }