diff --git a/composer.json b/composer.json
index 02ac24ab0..5b4369e00 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
     "nyholm/psr7": "^1.5",
     "phpbench/phpbench": "^1.2",
     "phpstan/extension-installer": "^1.1",
-    "phpstan/phpstan": "2.1.22",
+    "phpstan/phpstan": "2.1.23",
     "phpstan/phpstan-phpunit": "2.0.7",
     "phpstan/phpstan-strict-rules": "2.0.6",
     "phpunit/phpunit": "^9.5 || ^10.5.21 || ^11",
diff --git a/phpstan/include-by-php-version.php b/phpstan/include-by-php-version.php
index 1e6e5fc35..dd440c3a8 100644
--- a/phpstan/include-by-php-version.php
+++ b/phpstan/include-by-php-version.php
@@ -6,9 +6,6 @@
 if (version_compare($phpversion, '8.2', '>=')) {
     $includes[] = __DIR__ . '/php-at-least-8.2.neon';
 }
-if (version_compare($phpversion, '8.4', '<')) {
-    $includes[] = __DIR__ . '/php-below-8.4.neon';
-}
 if (version_compare($phpversion, '8.2', '<')) {
     $includes[] = __DIR__ . '/php-below-8.2.neon';
 }
diff --git a/phpstan/php-below-8.4.neon b/phpstan/php-below-8.4.neon
deleted file mode 100644
index bd3220b60..000000000
--- a/phpstan/php-below-8.4.neon
+++ /dev/null
@@ -1,7 +0,0 @@
-parameters:
-    ignoreErrors:
-        -
-            message: '#^Call\-site variance of covariant object in generic type ReflectionClass\<covariant object\> in PHPDoc tag @param for parameter \$class is redundant, template type T of object of class ReflectionClass has the same variance\.$#'
-            identifier: generics.callSiteVarianceRedundant
-            count: 1
-            path: ../generate-class-reference.php