diff --git a/config/config.sample.php b/config/config.sample.php
index 0e6480cbf059..0f04b8dcdcb7 100644
--- a/config/config.sample.php
+++ b/config/config.sample.php
@@ -880,6 +880,11 @@
 		'apps' => ['files_mediaviewer'],
 		'logfile' => '/tmp/mediaviewer.log'
 	],
+	[
+		# special sql query logging
+		'apps' => ['core/sql'],
+		'logfile' => __DIR__ . '/../data/sql.jsonl'
+	],
   ],
 
 /**
diff --git a/lib/kernel.php b/lib/kernel.php
index 05bd2b996aac..066bdb6dc746 100644
--- a/lib/kernel.php
+++ b/lib/kernel.php
@@ -64,6 +64,7 @@
  * No, we can not put this class in its own file because it is used by
  * OC_autoload!
  */
+/** @codeCoverageIgnore */
 class OC {
 	/**
 	 * Associative array for autoloading. classname => filename
@@ -551,12 +552,12 @@ public static function init() {
 		@\ini_set('log_errors', 1);
 
 		if (!\date_default_timezone_set('UTC')) {
-			\OC::$server->getLogger()->error('Could not set timezone to UTC');
-		};
+			self::$server->getLogger()->error('Could not set timezone to UTC');
+		}
 
-		//try to configure php to enable big file uploads.
-		//this doesn´t work always depending on the webserver and php configuration.
-		//Let´s try to overwrite some defaults anyway
+		// try to configure php to enable big file uploads.
+		// this doesn't work always depending on the webserver and php configuration.
+		// Let´s try to overwrite some defaults anyway
 
 		//try to set the maximum execution time to 60min
 		@\set_time_limit(3600);
@@ -685,6 +686,18 @@ public static function init() {
 			$lockProvider = \OC::$server->getLockingProvider();
 			$lockProvider->releaseAll();
 		});
+		$debug = \OC::$server->getConfig()->getSystemValue('debug', false);
+		if ($debug) {
+			\OC::$server->getShutdownHandler()->register(function () {
+				$queries = \OC::$server->getQueryLogger()->getQueries();
+				\OC::$server->getLogger()->debug("SQL query log", [
+					'app' => 'core/sql',
+					'extraFields' => [
+						'queries' => $queries
+					]
+				]);
+			});
+		}
 
 		// Check whether the sample configuration has been copied
 		if ($systemConfig->getValue('copied_sample_config', false)) {
diff --git a/lib/private/Diagnostics/Query.php b/lib/private/Diagnostics/Query.php
index cc754d906b93..7c6d2ce6a1ed 100644
--- a/lib/private/Diagnostics/Query.php
+++ b/lib/private/Diagnostics/Query.php
@@ -24,21 +24,21 @@
 
 use OCP\Diagnostics\IQuery;
 
-class Query implements IQuery {
-	private $sql;
+class Query implements IQuery, \JsonSerializable {
+	private string $sql;
 
-	private $params;
+	private array $params;
 
-	private $start;
+	private int $start;
 
-	private $end;
+	private int $end;
 
 	/**
 	 * @param string $sql
 	 * @param array $params
 	 * @param int $start
 	 */
-	public function __construct($sql, $params, $start) {
+	public function __construct(string $sql, $params, $start) {
 		$this->sql = $sql;
 		$this->params = $params;
 		$this->start = $start;
@@ -75,4 +75,14 @@ public function getStart() {
 	public function getDuration() {
 		return $this->end - $this->start;
 	}
+
+	public function jsonSerialize() {
+		return [
+			'query' => $this->sql,
+			'parameters' => $this->params,
+			'duration' => $this->getDuration(),
+			'start' => $this->start,
+			'end' => $this->end,
+		];
+	}
 }
diff --git a/tests/lib/Diagnostics/QueryLoggerTest.php b/tests/lib/Diagnostics/QueryLoggerTest.php
index 7fedf34abb7c..8f28400b1e87 100644
--- a/tests/lib/Diagnostics/QueryLoggerTest.php
+++ b/tests/lib/Diagnostics/QueryLoggerTest.php
@@ -31,7 +31,7 @@ class QueryLoggerTest extends TestCase {
 	public function setUp(): void {
 		parent::setUp();
 
-		$this->logger = new QueryLogger();
+		$this->logger = new QueryLogger(2444666668888888);
 	}
 
 	public function testQueryLogger(): void {
@@ -48,5 +48,17 @@ public function testQueryLogger(): void {
 
 		$queries = $this->logger->getQueries();
 		self::assertCount(1, $queries);
+
+		# assert json serialize
+		self::assertEquals([
+			'query' => 'SELECT',
+			'parameters' => [
+				'testuser',
+				'count'
+			],
+			'duration' => 0,
+			'start' => 2444666668888888,
+			'end' => 2444666668888888
+		], $queries[0]->jsonSerialize());
 	}
 }