diff --git a/app/bootstrap.php b/app/bootstrap.php
index a7aea8094f816..2e99d752b06cc 100644
--- a/app/bootstrap.php
+++ b/app/bootstrap.php
@@ -13,9 +13,8 @@
 }
 #ini_set('display_errors', 1);
 
-/* PHP version validation */
-if (!defined('PHP_VERSION_ID') || PHP_VERSION_ID < 80100) {
-    if (PHP_SAPI == 'cli') {
+if (PHP_VERSION_ID < 80100) {
+    if (PHP_SAPI === 'cli') {
         echo 'Magento supports PHP 8.1.0 or later. ' .
             'Please read https://experienceleague.adobe.com/docs/commerce-operations/installation-guide/system-requirements.html';
     } else {
@@ -31,16 +30,6 @@
     exit(1);
 }
 
-// PHP 8 compatibility. Define constants that are not present in PHP < 8.0
-if (!defined('PHP_VERSION_ID') || PHP_VERSION_ID < 80000) {
-    if (!defined('T_NAME_QUALIFIED')) {
-        define('T_NAME_QUALIFIED', 24001);
-    }
-    if (!defined('T_NAME_FULLY_QUALIFIED')) {
-        define('T_NAME_FULLY_QUALIFIED', 24002);
-    }
-}
-
 require_once __DIR__ . '/autoload.php';
 // Sets default autoload mappings, may be overridden in Bootstrap::create
 \Magento\Framework\App\Bootstrap::populateAutoloader(BP, []);
diff --git a/dev/tests/static/framework/bootstrap.php b/dev/tests/static/framework/bootstrap.php
index 28f8824221f5e..36a2966879a42 100644
--- a/dev/tests/static/framework/bootstrap.php
+++ b/dev/tests/static/framework/bootstrap.php
@@ -21,15 +21,6 @@
     define('TESTS_TEMP_DIR', dirname(__DIR__) . '/tmp');
 }
 
-// PHP 8 compatibility. Define constants that are not present in PHP < 8.0
-if (!defined('PHP_VERSION_ID') || PHP_VERSION_ID < 80000) {
-    if (!defined('T_NAME_QUALIFIED')) {
-        define('T_NAME_QUALIFIED', 24001);
-    }
-    if (!defined('T_NAME_FULLY_QUALIFIED')) {
-        define('T_NAME_FULLY_QUALIFIED', 24002);
-    }
-}
 
 setCustomErrorHandler();
 
diff --git a/dev/tests/unit/framework/bootstrap.php b/dev/tests/unit/framework/bootstrap.php
index 31eab08d1221a..24902cfda984b 100644
--- a/dev/tests/unit/framework/bootstrap.php
+++ b/dev/tests/unit/framework/bootstrap.php
@@ -10,16 +10,6 @@
     define('TESTS_TEMP_DIR', dirname(__DIR__) . '/tmp');
 }
 
-// PHP 8 compatibility. Define constants that are not present in PHP < 8.0
-if (!defined('PHP_VERSION_ID') || PHP_VERSION_ID < 80000) {
-    if (!defined('T_NAME_QUALIFIED')) {
-        define('T_NAME_QUALIFIED', 24001);
-    }
-    if (!defined('T_NAME_FULLY_QUALIFIED')) {
-        define('T_NAME_FULLY_QUALIFIED', 24002);
-    }
-}
-
 require_once __DIR__ . '/autoload.php';
 
 setCustomErrorHandler();
@@ -59,7 +49,7 @@ function ($errNo, $errStr, $errFile, $errLine) {
                     E_USER_DEPRECATED => 'User Deprecated',
                 ];
 
-                $errName = isset($errorNames[$errNo]) ? $errorNames[$errNo] : "";
+                $errName = $errorNames[$errNo] ?? "";
 
                 throw new \PHPUnit\Framework\Exception(
                     sprintf("%s: %s in %s:%s.", $errName, $errStr, $errFile, $errLine),
diff --git a/lib/internal/Magento/Framework/DB/DataConverter/SerializedToJson.php b/lib/internal/Magento/Framework/DB/DataConverter/SerializedToJson.php
index bc31cb91ecede..620cc1f0806e1 100644
--- a/lib/internal/Magento/Framework/DB/DataConverter/SerializedToJson.php
+++ b/lib/internal/Magento/Framework/DB/DataConverter/SerializedToJson.php
@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2016 Adobe
+ * All rights reserved.
  */
 namespace Magento\Framework\DB\DataConverter;
 
@@ -95,15 +95,7 @@ protected function unserializeValue($value)
     /**
      * Encode value with json encoder.
      *
-     * In PHP version < 7.1.0 serialize() uses PG(serialize_precision) which set to 17 be default.
-     * Since json_encode() uses EG(precision) which set to 14 be default, json_encode() removes lower digits of
-     * fraction parts and destroys original value even if PHP's float could hold more precise float value.
-     * To prevent this issue EG(precision) is set to 17 to be equal with PG(serialize_precision) during
-     * data converting from serialized format to JSON.
-     *
-     * In PHP version >= 7.1.0 serialize() and json_encode() use PG(serialize_precision) which set to -1 be default.
-     * Setting -1 uses better algorithm for rounding float numbers.
-     * But for data consistency during converting process PG(serialize_precision) is set to 17.
+     * For data consistency during converting process PG(serialize_precision) is set to 17.
      *
      * @param string $value
      * @return string
@@ -111,20 +103,13 @@ protected function unserializeValue($value)
      */
     protected function encodeJson($value)
     {
-        $storedPrecision = ini_get('precision');
         $storedSerializePrecision = ini_get('serialize_precision');
 
-        if (PHP_VERSION_ID < 70100) {
-            // In PHP version < 7.1.0 json_encode() uses EG(precision).
-            ini_set('precision', 17);
-        } else {
-            // In PHP version >= 7.1.0 json_encode() uses PG(serialize_precision).
-            ini_set('serialize_precision', 17);
-        }
+        // In PHP 8.1+ json_encode() uses PG(serialize_precision)
+        ini_set('serialize_precision', 17);
 
         $value = $this->json->serialize($value);
 
-        ini_set('precision', $storedPrecision);
         ini_set('serialize_precision', $storedSerializePrecision);
 
         if (json_last_error()) {
diff --git a/lib/internal/Magento/Framework/DB/Test/Unit/DB/Statement/MysqlTest.php b/lib/internal/Magento/Framework/DB/Test/Unit/DB/Statement/MysqlTest.php
index 45efccba28ca9..ae50aade8b7a7 100644
--- a/lib/internal/Magento/Framework/DB/Test/Unit/DB/Statement/MysqlTest.php
+++ b/lib/internal/Magento/Framework/DB/Test/Unit/DB/Statement/MysqlTest.php
@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2019 Adobe
+ * All rights reserved.
  */
 declare(strict_types=1);
 
@@ -189,10 +189,7 @@ private function setQueryStringForPdoStmtMock(string $query): void
         /*
          * In PHP 8.1 $queryString is a Typed property, thus it should be initialized before the 1st call.
          * But it's not automatically initialized in case of Mocking, so we do it here.
-         * Note: In PHP < 8.1 such assignment prohibited.
          */
-        if (PHP_VERSION_ID >= 80100) {
-            $this->pdoStatementMock->queryString = $query;
-        }
+        $this->pdoStatementMock->queryString = $query;
     }
 }