diff --git a/composer.json b/composer.json
index 3bfa30b..cfeca10 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
 	},
 	"config": {
 		"platform": {
-			"php": "7.4"
+			"php": "8.0"
 		}
 	}
 }
diff --git a/composer.lock b/composer.lock
index 9fb3687..7bb4677 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "5c7be477b217d6074abc6c2f8d2c2256",
+    "content-hash": "7b806afecf0b4bd9cf2aed44f533eaf4",
     "packages": [],
     "packages-dev": [
         {
@@ -389,7 +389,7 @@
     "platform": [],
     "platform-dev": [],
     "platform-overrides": {
-        "php": "7.4"
+        "php": "8.0"
     },
     "plugin-api-version": "2.3.0"
 }
diff --git a/lib/Controller/PageController.php b/lib/Controller/PageController.php
index 2647b81..266a1a4 100644
--- a/lib/Controller/PageController.php
+++ b/lib/Controller/PageController.php
@@ -167,10 +167,7 @@ class PageController extends Controller {
 		];
 	}
 
-	/**
-	 * @param mixed $value
-	 */
-	private function toJson($value): string {
+	private function toJson(array $value): string {
 		return htmlspecialchars(json_encode($value), ENT_QUOTES, 'UTF-8');
 	}
 }
diff --git a/lib/Db/ReaderEntity.php b/lib/Db/ReaderEntity.php
index 6fa301d..66eb48a 100644
--- a/lib/Db/ReaderEntity.php
+++ b/lib/Db/ReaderEntity.php
@@ -24,7 +24,7 @@ abstract class ReaderEntity extends Entity {
 	 *
 	 * @return string|array
 	 */
-	public function conditional_json_decode(string $el) {
+	public function conditional_json_decode(string $el): mixed {
 		/** @var array $result */
 		$result = json_decode($el);
 		if (json_last_error() === JSON_ERROR_NONE) {
diff --git a/lib/Hooks.php b/lib/Hooks.php
index 8ddfe7d..3c99361 100644
--- a/lib/Hooks.php
+++ b/lib/Hooks.php
@@ -79,10 +79,7 @@ class Hooks {
 		$queryBuilder->executeStatement();
 	}
 
-	/**
-	 * @param mixed $string
-	 */
-	private static function isJson($string): bool {
+	private static function isJson(mixed $string): bool {
 		return is_string($string) && is_array(json_decode($string, true)) && json_last_error() == JSON_ERROR_NONE;
 	}
 }