diff --git a/Classes/Utility/TimingUtility.php b/Classes/Utility/TimingUtility.php
index 05814b6..e00367a 100644
--- a/Classes/Utility/TimingUtility.php
+++ b/Classes/Utility/TimingUtility.php
@@ -22,6 +22,8 @@ final class TimingUtility implements SingletonInterface
 {
     public const MAX_SINGLE_HEADER_SIZE = 2 ** 12;
 
+    private static ?TimingUtility $instance = null;
+
     private bool $registered = false;
 
     /** @var bool */
@@ -41,7 +43,7 @@ public function __construct(private readonly RegisterShutdownFunctionInterface $
 
     public static function getInstance(): TimingUtility
     {
-        return GeneralUtility::makeInstance(TimingUtility::class, new RegisterShutdownFunction(), new ConfigService());
+        return static::$instance ??= GeneralUtility::makeInstance(TimingUtility::class, new RegisterShutdownFunction(), new ConfigService());
     }
 
     /** @var StopWatch[] */
diff --git a/Tests/TimingUtilityTest.php b/Tests/TimingUtilityTest.php
index dabdcd4..04f5176 100644
--- a/Tests/TimingUtilityTest.php
+++ b/Tests/TimingUtilityTest.php
@@ -48,6 +48,10 @@ protected function tearDown(): void
     public function getInstance(): void
     {
         self::assertInstanceOf(TimingUtility::class, $firstCall = TimingUtility::getInstance());
+        // even if we clear GeneralUtility, the instance should be the same
+        // we measure so erly in TYPO3s bootstrap, that GeneralUtility singletons are cleared after our first measurement
+        // but we need to be sure, that the instance is not recreated as that will run the shutdown function again, and that is not good!
+        GeneralUtility::resetSingletonInstances([]);
         self::assertSame($firstCall, TimingUtility::getInstance());
     }
 
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index bffe951..bd8c450 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -789,7 +789,7 @@ parameters:
 			path: Tests/TimingUtilityTest.php
 
 		-
-			message: '#^Method Kanti\\ServerTiming\\Service\\SentryServiceInterface@anonymous/Tests/TimingUtilityTest\.php\:305\:\:sendSentryTrace\(\) never returns null so it can be removed from the return type\.$#'
+			message: '#^Method Kanti\\ServerTiming\\Service\\SentryServiceInterface@anonymous/Tests/TimingUtilityTest\.php\:[0-9]+\:\:sendSentryTrace\(\) never returns null so it can be removed from the return type\.$#'
 			identifier: return.unusedType
 			count: 1
 			path: Tests/TimingUtilityTest.php