diff --git a/.gitattributes b/.gitattributes
index 2b5b6cd..15b1467 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,6 +1,8 @@
-.github          export-ignore
-.gitattributes   export-ignore
-.gitignore       export-ignore
-.travis.yml      export-ignore
-phpunit.xml.dist export-ignore
-tests            export-ignore
+.github                export-ignore
+.gitattributes         export-ignore
+.gitignore             export-ignore
+.travis.yml            export-ignore
+.php-cs-fixer.dist.php export-ignore
+phpstan.neon           export-ignore
+phpunit.xml.dist       export-ignore
+tests                  export-ignore
diff --git a/src/DateTimeFormatter.php b/src/DateTimeFormatter.php
index 2203326..aa4687a 100644
--- a/src/DateTimeFormatter.php
+++ b/src/DateTimeFormatter.php
@@ -18,8 +18,8 @@ public function __construct(private TranslatorInterface $translator)
      */
     public function formatDiff(
         int|string|\DateTimeInterface $from,
-        int|string|\DateTimeInterface $to = null,
-        string $locale = null
+        int|string|\DateTimeInterface|null $to = null,
+        ?string $locale = null
     ): string {
         $from = self::formatDateTime($from);
         $to = self::formatDateTime($to);
@@ -53,7 +53,7 @@ public function formatDiff(
      *
      * @source https://github.com/symfony/symfony/blob/ad72245261792c6b5d2db821fcbd141b11095215/src/Symfony/Component/Console/Helper/Helper.php#L97
      */
-    public function formatDuration(float $seconds, string $locale = null): string
+    public function formatDuration(float $seconds, ?string $locale = null): string
     {
         static $timeFormats = [
             [0, 'duration.none'],
@@ -94,8 +94,8 @@ public function formatDuration(float $seconds, string $locale = null): string
      */
     public function formatAge(
         int|string|\DateTimeInterface $from,
-        int|string|\DateTimeInterface $to = null,
-        string $locale = null
+        int|string|\DateTimeInterface|null $to = null,
+        ?string $locale = null
     ): string {
         $from = self::formatDateTime($from);
         $to = self::formatDateTime($to);