diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0075d4f..4286276 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
       matrix:
         os: [ ubuntu-latest, macos-latest, windows-latest ]
         # All supported PHP versions https://www.php.net/supported-versions.php
-        php: [ '7.3', '7.4', '8.0', '8.1' ]
+        php: [ '8.2','8.3','8.4' ]
 
     runs-on: ${{matrix.os}}
 
diff --git a/src/Oauth/PhpFlickrService.php b/src/Oauth/PhpFlickrService.php
index 6bb3220..8e03122 100644
--- a/src/Oauth/PhpFlickrService.php
+++ b/src/Oauth/PhpFlickrService.php
@@ -21,7 +21,7 @@ public function __construct(
         ClientInterface $httpClient,
         TokenStorageInterface $storage,
         SignatureInterface $signature,
-        UriInterface $baseApiUri = null
+        ?UriInterface $baseApiUri = null
     ) {
         if ($baseApiUri === null) {
             $baseApiUri = new Uri(static::$baseUrl . '/rest/');
diff --git a/src/PhotosApi.php b/src/PhotosApi.php
index 530498d..0e472c9 100644
--- a/src/PhotosApi.php
+++ b/src/PhotosApi.php
@@ -847,9 +847,9 @@ public function setContentType($photoId, $contentType)
      */
     public function setDates(
         $photoId,
-        DateTime $dateTaken = null,
+        DateTime|null $dateTaken = null,
         $dateTakenGranularity = null,
-        DateTime $datePosted = null
+        DateTime|null $datePosted = null
     ) {
         $args = ['photo_id' => $photoId];
         if (!empty($dateTaken)) {
diff --git a/src/PhpFlickr.php b/src/PhpFlickr.php
index b2c2a12..7b88d01 100644
--- a/src/PhpFlickr.php
+++ b/src/PhpFlickr.php
@@ -81,7 +81,7 @@ class PhpFlickr
      * @param string $apiKey
      * @param string|null $secret
      */
-    public function __construct(string $apiKey, string $secret = null)
+    public function __construct(string $apiKey, string|null $secret = null)
     {
         $this->api_key = $apiKey;
         $this->secret = $secret;