diff --git a/src/AnimeClient/API/Kitsu/Transformer/AnimeTransformer.php b/src/AnimeClient/API/Kitsu/Transformer/AnimeTransformer.php
index 39b84dd4..759c07c3 100644
--- a/src/AnimeClient/API/Kitsu/Transformer/AnimeTransformer.php
+++ b/src/AnimeClient/API/Kitsu/Transformer/AnimeTransformer.php
@@ -36,7 +36,7 @@ final class AnimeTransformer extends AbstractTransformer
 		$characters = [];
 		$links = [];
 		$staff = [];
-		$rawGenres = array_filter($base['categories']['nodes'], static fn ($c) => $c !== null);
+		$rawGenres = array_filter($base['categories']['nodes'], static fn ($c) => $c !== NULL);
 		$genres = array_map(static fn ($genre) => $genre['title']['en'], $rawGenres);
 
 		sort($genres);
diff --git a/src/AnimeClient/API/Kitsu/Transformer/PersonTransformer.php b/src/AnimeClient/API/Kitsu/Transformer/PersonTransformer.php
index 6723950e..67d570a4 100644
--- a/src/AnimeClient/API/Kitsu/Transformer/PersonTransformer.php
+++ b/src/AnimeClient/API/Kitsu/Transformer/PersonTransformer.php
@@ -98,7 +98,7 @@ final class PersonTransformer extends AbstractTransformer
 		{
 			foreach ($data['voices']['nodes'] as $voicing)
 			{
-				if ($voicing === null)
+				if ($voicing === NULL)
 				{
 					continue;
 				}
diff --git a/src/AnimeClient/API/Kitsu/Transformer/UserTransformer.php b/src/AnimeClient/API/Kitsu/Transformer/UserTransformer.php
index 271eb798..b31982fa 100644
--- a/src/AnimeClient/API/Kitsu/Transformer/UserTransformer.php
+++ b/src/AnimeClient/API/Kitsu/Transformer/UserTransformer.php
@@ -40,8 +40,8 @@ final class UserTransformer extends AbstractTransformer
 
 		return User::from([
 			'about' => $base['about'] ?? '',
-			'avatar' => $base['avatarImage']['original']['url'] ?? null,
-			'birthday' => $base['birthday'] !== null ? Kitsu::formatDate($base['birthday']) . ' (' . Kitsu::friendlyTime(Kitsu::getDateDiff($base['birthday']), 'year') . ')' : null,
+			'avatar' => $base['avatarImage']['original']['url'] ?? NULL,
+			'birthday' => $base['birthday'] !== NULL ? Kitsu::formatDate($base['birthday']) . ' (' . Kitsu::friendlyTime(Kitsu::getDateDiff($base['birthday']), 'year') . ')' : NULL,
 			'joinDate' => Kitsu::formatDate($base['createdAt']) . ' (' . Kitsu::friendlyTime(Kitsu::getDateDiff($base['createdAt']), 'day') . ' ago)',
 			'gender' => $base['gender'],
 			'favorites' => $this->organizeFavorites($favorites),
@@ -50,7 +50,7 @@ final class UserTransformer extends AbstractTransformer
 			'slug' => $base['slug'],
 			'stats' => $this->organizeStats($stats),
 			'waifu' => $waifu,
-			'website' => $base['siteLinks']['nodes'][0]['url'] ?? null,
+			'website' => $base['siteLinks']['nodes'][0]['url'] ?? NULL,
 		]);
 	}
 
diff --git a/src/AnimeClient/Controller/User.php b/src/AnimeClient/Controller/User.php
index a44de592..c87093f7 100644
--- a/src/AnimeClient/Controller/User.php
+++ b/src/AnimeClient/Controller/User.php
@@ -69,9 +69,10 @@ final class User extends BaseController
 			: $username;
 
 		$rawData = $this->kitsuModel->getUserData($username);
-		if ($rawData['data']['findProfileBySlug'] === null)
+		if ($rawData['data']['findProfileBySlug'] === NULL)
 		{
 			$this->notFound('Sorry, user not found', "The user '$username' does not seem to exist.");
+
 			return;
 		}
 
diff --git a/src/AnimeClient/Kitsu.php b/src/AnimeClient/Kitsu.php
index 1d8ee6b1..456b83a5 100644
--- a/src/AnimeClient/Kitsu.php
+++ b/src/AnimeClient/Kitsu.php
@@ -142,7 +142,7 @@ final class Kitsu
 		$now = new DateTimeImmutable();
 		$then = new DateTimeImmutable($date);
 
-		$interval = $now->diff($then, true);
+		$interval = $now->diff($then, TRUE);
 
 		$years = $interval->y * self::SECONDS_IN_MINUTE * self::MINUTES_IN_YEAR;
 		$days = $interval->d * self::SECONDS_IN_MINUTE * self::MINUTES_IN_DAY;