diff --git a/typo3/sysext/core/Build/UnitTestsBootstrap.php b/typo3/sysext/core/Build/UnitTestsBootstrap.php
index 4ec5fe42c89c72f28dc9112ca80fb5727b0e146a..bfebaa8fcc47978271d99b9af58ee1ce173e6e33 100644
--- a/typo3/sysext/core/Build/UnitTestsBootstrap.php
+++ b/typo3/sysext/core/Build/UnitTestsBootstrap.php
@@ -134,6 +134,10 @@ class UnitTestsBootstrap
         define('TYPO3_cliMode', true);
         putenv('TYPO3_CONTEXT=Testing');
 
+        // Set TYPO3_AJAX and define TYPO3_REQUESSTTYPE's to prevent PHP 7.2 warnings
+        $GLOBALS['TYPO3_AJAX'] = '';
+        Bootstrap::getInstance()->defineTypo3RequestTypes();
+
         return $this;
     }
 
diff --git a/typo3/sysext/core/Classes/Core/Bootstrap.php b/typo3/sysext/core/Classes/Core/Bootstrap.php
index 145644fc864fc01c56de9343a9bd58e4cece687f..91b28c44feb742fcc6c2eff8a7a22a01be8bfeb9 100644
--- a/typo3/sysext/core/Classes/Core/Bootstrap.php
+++ b/typo3/sysext/core/Classes/Core/Bootstrap.php
@@ -738,7 +738,7 @@ class Bootstrap
      *
      * @return Bootstrap
      */
-    protected function defineTypo3RequestTypes()
+    public function defineTypo3RequestTypes()
     {
         define('TYPO3_REQUESTTYPE_FE', 1);
         define('TYPO3_REQUESTTYPE_BE', 2);