diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 844df1d..a02bd39 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -128,7 +128,7 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                php: ['7.2', '7.3', '7.4', '8.0']
+                php: ['7.1','7.2', '7.3', '7.4', '8.0']
 
             fail-fast: false
 
diff --git a/composer.json b/composer.json
index 41839da..86cfbd4 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
         }
     ],
     "require": {
-        "php": ">=7.2",
+        "php": ">=7.1",
         "mpdf/mpdf": "^8.0"
     },
     "require-dev": {
@@ -31,7 +31,7 @@
         "nette/application": "~3.0.0",
         "nette/di": "^3.0",
         "ninjify/nunjuck": "^0.3.0",
-        "ninjify/qa": "^0.12.1",
+        "ninjify/qa": "^0.12",
         "phpstan/phpstan": "^0.12",
         "phpstan/phpstan-deprecation-rules": "^0.12",
         "phpstan/phpstan-nette": "^0.12",
diff --git a/phpstan.neon b/phpstan.neon
index bca4d7c..c118e25 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -9,4 +9,3 @@ parameters:
     ignoreErrors:
         - '#Variable property access on Mpdf\\Mpdf#'
     treatPhpDocTypesAsCertain: false
-    checkMissingIterableValueType: false
diff --git a/src/PdfResponse.php b/src/PdfResponse.php
index f9a4112..0c5e4f8 100644
--- a/src/PdfResponse.php
+++ b/src/PdfResponse.php
@@ -89,10 +89,10 @@ class PdfResponse implements Nette\Application\IResponse
 
 	public const LAYOUT_DEFAULT = 'default'; // User’s default setting in Adobe Reader
 
-	/** @var array */
+	/** @var array<mixed> */
 	public $mpdfConfig = [];
 
-	/** @var array onBeforeComplete event */
+	/** @var array<mixed> onBeforeComplete event */
 	public $onBeforeComplete = [];
 
 	/** @var string Additional stylesheet as a html string */
@@ -128,7 +128,7 @@ class PdfResponse implements Nette\Application\IResponse
 	/** @var string ORIENTATION_PORTRAIT or ORIENTATION_LANDSCAPE */
 	private $pageOrientation = self::ORIENTATION_PORTRAIT;
 
-	/** @var string|array see second parameter ($format) at https://mpdf.github.io/reference/mpdf-functions/mpdf.html */
+	/** @var string|array<mixed> see second parameter ($format) at https://mpdf.github.io/reference/mpdf-functions/mpdf.html */
 	private $pageFormat = 'A4';
 
 	/** @var string margins: top, right, bottom, left, header, footer */
@@ -163,33 +163,21 @@ public function setTemplate($source): self
 		return $this;
 	}
 
-	/**
-	 * @return string
-	 */
 	public function getDocumentAuthor(): string
 	{
 		return $this->documentAuthor;
 	}
 
-	/**
-	 * @param string $documentAuthor
-	 */
 	public function setDocumentAuthor(string $documentAuthor): void
 	{
 		$this->documentAuthor = $documentAuthor;
 	}
 
-	/**
-	 * @return string
-	 */
 	public function getDocumentTitle(): string
 	{
 		return $this->documentTitle;
 	}
 
-	/**
-	 * @param string $documentTitle
-	 */
 	public function setDocumentTitle(string $documentTitle): void
 	{
 		$this->documentTitle = $documentTitle;
@@ -220,9 +208,6 @@ public function setDisplayZoom($displayZoom): void
 		$this->displayZoom = $displayZoom;
 	}
 
-	/**
-	 * @return string
-	 */
 	public function getDisplayLayout(): string
 	{
 		return $this->displayLayout;
@@ -252,41 +237,26 @@ public function setDisplayLayout(string $displayLayout): void
 		$this->displayLayout = $displayLayout;
 	}
 
-	/**
-	 * @return bool
-	 */
 	public function isMultiLanguage(): bool
 	{
 		return $this->multiLanguage;
 	}
 
-	/**
-	 * @param bool $multiLanguage
-	 */
 	public function setMultiLanguage(bool $multiLanguage): void
 	{
 		$this->multiLanguage = $multiLanguage;
 	}
 
-	/**
-	 * @return bool
-	 */
 	public function isIgnoreStylesInHTMLDocument(): bool
 	{
 		return $this->ignoreStylesInHTMLDocument;
 	}
 
-	/**
-	 * @param bool $ignoreStylesInHTMLDocument
-	 */
 	public function setIgnoreStylesInHTMLDocument(bool $ignoreStylesInHTMLDocument): void
 	{
 		$this->ignoreStylesInHTMLDocument = $ignoreStylesInHTMLDocument;
 	}
 
-	/**
-	 * @return string
-	 */
 	public function getSaveMode(): string
 	{
 		return $this->saveMode;
@@ -296,7 +266,6 @@ public function getSaveMode(): string
 	 * To force download, use PdfResponse::DOWNLOAD
 	 * To show pdf in browser, use PdfResponse::INLINE
 	 *
-	 * @param string $saveMode
 	 * @throws InvalidArgumentException
 	 */
 	public function setSaveMode(string $saveMode): void
@@ -308,16 +277,12 @@ public function setSaveMode(string $saveMode): void
 		$this->saveMode = $saveMode;
 	}
 
-	/**
-	 * @return string
-	 */
 	public function getPageOrientation(): string
 	{
 		return $this->pageOrientation;
 	}
 
 	/**
-	 * @param string $pageOrientation
 	 * @throws InvalidStateException
 	 * @throws InvalidArgumentException
 	 */
@@ -335,7 +300,7 @@ public function setPageOrientation(string $pageOrientation): void
 	}
 
 	/**
-	 * @return string|array
+	 * @return string|array<mixed>
 	 */
 	public function getPageFormat()
 	{
@@ -343,7 +308,7 @@ public function getPageFormat()
 	}
 
 	/**
-	 * @param string|array $pageFormat
+	 * @param string|array<mixed> $pageFormat
 	 * @throws InvalidStateException
 	 */
 	public function setPageFormat($pageFormat): void
@@ -355,9 +320,6 @@ public function setPageFormat($pageFormat): void
 		$this->pageFormat = $pageFormat;
 	}
 
-	/**
-	 * @return string
-	 */
 	public function getPageMargins(): string
 	{
 		return $this->pageMargins;
@@ -366,7 +328,7 @@ public function getPageMargins(): string
 	/**
 	 * Gets margins as array
 	 *
-	 * @return array
+	 * @return array<mixed>
 	 */
 	public function getMargins(): array
 	{
@@ -383,7 +345,6 @@ public function getMargins(): array
 	}
 
 	/**
-	 * @param string $pageMargins
 	 * @throws InvalidStateException
 	 * @throws InvalidArgumentException
 	 */
@@ -412,7 +373,6 @@ public function setPageMargins(string $pageMargins): void
 	 * WARNING: internally creates mPDF instance, setting some properties after calling this method
 	 * may cause an Exception
 	 *
-	 * @param string $pathToBackgroundTemplate
 	 * @throws FileNotFoundException
 	 * @throws PdfParserExceptionAlias
 	 */
@@ -431,9 +391,11 @@ public function setBackgroundTemplate(string $pathToBackgroundTemplate): void
 			$tplId = $mpdf->importPage($i);
 			$mpdf->useTemplate($tplId);
 
-			if ($i < $pagecount) {
-				$mpdf->AddPage();
+			if ($i >= $pagecount) {
+				continue;
 			}
+
+			$mpdf->AddPage();
 		}
 
 		$mpdf->page = 1;
@@ -462,7 +424,6 @@ protected function getMPDFConfig(): array
 	}
 
 	/**
-	 * @return Mpdf
 	 * @throws InvalidStateException
 	 */
 	public function getMPDF(): Mpdf
@@ -494,9 +455,11 @@ public function getMPDF(): Mpdf
 	 */
 	public function __construct($source = null)
 	{
-		if ($source !== null) {
-			$this->setTemplate($source);
+		if ($source === null) {
+			return;
 		}
+
+		$this->setTemplate($source);
 	}
 
 
@@ -507,7 +470,6 @@ public function __construct($source = null)
 	/**
 	 * Builds final pdf
 	 *
-	 * @return Mpdf
 	 * @throws InvalidStateException
 	 * @throws MissingServiceException
 	 * @throws MpdfException
@@ -620,9 +582,6 @@ private function build(): Mpdf
 	/**
 	 * Sends response to output
 	 *
-	 * @param IRequest  $httpRequest
-	 * @param IResponse $httpResponse
-	 * @return void
 	 * @throws MpdfException
 	 */
 	public function send(IRequest $httpRequest, IResponse $httpResponse): void
@@ -636,8 +595,6 @@ public function send(IRequest $httpRequest, IResponse $httpResponse): void
 	 * Note: $name overrides property $documentTitle
 	 *
 	 * @param string      $dir path to directory
-	 * @param string|null $filename
-	 * @return string
 	 * @throws MpdfException
 	 */
 	public function save(string $dir, ?string $filename = null): string
@@ -658,7 +615,6 @@ public function save(string $dir, ?string $filename = null): string
 	}
 
 	/**
-	 * @return string
 	 * @throws MpdfException
 	 */
 	public function toString(): string
@@ -669,8 +625,6 @@ public function toString(): string
 
 	/**
 	 * Return generated PDF as a string
-	 *
-	 * @return string
 	 */
 	public function __toString(): string
 	{
diff --git a/src/PdfResponseFactory.php b/src/PdfResponseFactory.php
index abd3408..f4e1bdb 100644
--- a/src/PdfResponseFactory.php
+++ b/src/PdfResponseFactory.php
@@ -5,9 +5,10 @@
 class PdfResponseFactory
 {
 
-	/** @var array */
+	/** @var array<mixed> */
 	public $mpdfConfig;
 
+	/** @param array<mixed> $mpdfConfig */
 	public function __construct(array $mpdfConfig)
 	{
 		$this->mpdfConfig = $mpdfConfig;
diff --git a/tests/PdfResponse/PdfResponse.full.phpt b/tests/PdfResponse/PdfResponse.full.phpt
index 78b24fa..84fd16b 100644
--- a/tests/PdfResponse/PdfResponse.full.phpt
+++ b/tests/PdfResponse/PdfResponse.full.phpt
@@ -13,7 +13,7 @@ use Tester\Assert;
 require __DIR__ . '/../bootstrap.php';
 
 test(
-	function () {
+	function (): void {
 		$origData = file_get_contents(__DIR__ . '/templates/example1.htm');
 		$fileResponse = new PdfResponse($origData);
 		$fileResponse->setSaveMode(PdfResponse::INLINE);
diff --git a/tests/PdfResponse/PdfResponse.page.format.phpt b/tests/PdfResponse/PdfResponse.page.format.phpt
index 70ef900..2c9d714 100644
--- a/tests/PdfResponse/PdfResponse.page.format.phpt
+++ b/tests/PdfResponse/PdfResponse.page.format.phpt
@@ -17,7 +17,7 @@ require __DIR__ . '/../bootstrap.php';
 $origData = file_get_contents(__DIR__ . '/templates/example1.htm');
 
 test(
-	function () use ($origData) {
+	function () use ($origData): void {
 		$fileResponse = new PdfResponse($origData);
 		$fileResponse->setSaveMode(PdfResponse::INLINE);
 		$fileResponse->pageOrientation = PdfResponse::ORIENTATION_LANDSCAPE;
@@ -33,12 +33,12 @@ test(
 );
 
 test(
-	function () use ($origData) {
+	function () use ($origData): void {
 		$fileResponse = new PdfResponse($origData);
 		$fileResponse->getMPDF();
 
 		Assert::exception(
-			function () use ($fileResponse) {
+			function () use ($fileResponse): void {
 				$fileResponse->pageOrientation = PdfResponse::ORIENTATION_LANDSCAPE;
 			},
 			InvalidStateException::class,
@@ -48,12 +48,12 @@ test(
 );
 
 test(
-	function () use ($origData) {
+	function () use ($origData): void {
 		$fileResponse = new PdfResponse($origData);
 		$fileResponse->getMPDF();
 
 		Assert::exception(
-			function () use ($fileResponse) {
+			function () use ($fileResponse): void {
 				$fileResponse->pageFormat = 'A4-L';
 			},
 			InvalidStateException::class,
@@ -63,12 +63,12 @@ test(
 );
 
 test(
-	function () use ($origData) {
+	function () use ($origData): void {
 		$fileResponse = new PdfResponse($origData);
 		$fileResponse->getMPDF();
 
 		Assert::exception(
-			function () use ($fileResponse) {
+			function () use ($fileResponse): void {
 				$fileResponse->pageMargins = $fileResponse->getPageMargins();
 			},
 			InvalidStateException::class,
diff --git a/tests/PdfResponse/PdfResponse.save.phpt b/tests/PdfResponse/PdfResponse.save.phpt
index 16ab16c..d3ab6db 100644
--- a/tests/PdfResponse/PdfResponse.save.phpt
+++ b/tests/PdfResponse/PdfResponse.save.phpt
@@ -10,7 +10,7 @@ use Tester\Assert;
 require __DIR__ . '/../bootstrap.php';
 
 test(
-	function () {
+	function (): void {
 		$origData = file_get_contents(__DIR__ . '/templates/example1.htm');
 		$fileResponse = new PdfResponse($origData);
 		$fileResponse->setSaveMode(PdfResponse::DOWNLOAD);
diff --git a/tests/PdfResponse/PdfResponse.setters.phpt b/tests/PdfResponse/PdfResponse.setters.phpt
index 81f9474..2782be1 100644
--- a/tests/PdfResponse/PdfResponse.setters.phpt
+++ b/tests/PdfResponse/PdfResponse.setters.phpt
@@ -11,7 +11,7 @@ use Tester\Assert;
 require __DIR__ . '/../bootstrap.php';
 
 test(
-	function () {
+	function (): void {
 		$origData = file_get_contents(__DIR__ . '/templates/example1.htm');
 		$fileResponse = new PdfResponse($origData);
 
@@ -19,7 +19,7 @@ test(
 		$fileResponse->displayZoom = PdfResponse::ZOOM_REAL;
 		$fileResponse->displayZoom = 90;
 		Assert::exception(
-			function () use ($fileResponse) {
+			function () use ($fileResponse): void {
 				$fileResponse->displayZoom = 'invalid';
 			},
 			InvalidArgumentException::class
@@ -28,7 +28,7 @@ test(
 		// layout
 		$fileResponse->displayLayout = PdfResponse::LAYOUT_TWO;
 		Assert::exception(
-			function () use ($fileResponse) {
+			function () use ($fileResponse): void {
 				$fileResponse->displayLayout = 'invalid';
 			},
 			InvalidArgumentException::class
diff --git a/tests/PdfResponse/PdfResponse.symfony.crawler.phpt b/tests/PdfResponse/PdfResponse.symfony.crawler.phpt
index 4fcff39..0fa0105 100644
--- a/tests/PdfResponse/PdfResponse.symfony.crawler.phpt
+++ b/tests/PdfResponse/PdfResponse.symfony.crawler.phpt
@@ -13,7 +13,7 @@ use Tester\Assert;
 require __DIR__ . '/../bootstrap.php';
 
 test(
-	function () {
+	function (): void {
 		$origData = file_get_contents(__DIR__ . '/templates/example2.htm');
 		$fileResponse = new PdfResponse($origData);
 		$fileResponse->setSaveMode(PdfResponse::INLINE);
diff --git a/tests/PdfResponse/PdfResponseFactory.phpt b/tests/PdfResponse/PdfResponseFactory.phpt
index ccf9918..5d84451 100644
--- a/tests/PdfResponse/PdfResponseFactory.phpt
+++ b/tests/PdfResponse/PdfResponseFactory.phpt
@@ -7,7 +7,7 @@ use Tester\Assert;
 require __DIR__ . '/../bootstrap.php';
 
 test(
-	function () {
+	function (): void {
 		$author = 'Jan Novák';
 		$mpdfTmpDir = 'tmp/mpdf';
 
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 5c8681c..01956c4 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -17,30 +17,6 @@
 @mkdir(dirname(TEMP_DIR)); // @ - directory may already exist
 Tester\Helpers::purge(TEMP_DIR);
 
-function test(Closure $function)
-{
-	$function();
-}
-
-class Notes
-{
-
-	public static $notes = [];
-
-	public static function add($message)
-	{
-		self::$notes[] = $message;
-	}
-
-	public static function fetch()
-	{
-		$res = self::$notes;
-		self::$notes = [];
-		return $res;
-	}
-
-}
-
 function getTempDir(): string
 {
 	$dir = __DIR__ . '/tmp/' . getenv(Tester\Environment::THREAD);
@@ -61,7 +37,10 @@ function getTempDir(): string
 	return $dir;
 }
 
-function createContainer($source, $config = null, $params = []): ?Nette\DI\Container
+/**
+ * @param array<mixed> $params
+ */
+function createContainer(Nette\DI\Compiler $source, ?string $config = null, array $params = []): ?Nette\DI\Container
 {
 	$class = 'Container' . md5((string) lcg_value());
 	if ($source instanceof Nette\DI\ContainerBuilder) {