diff --git a/inc/Data/Driver/ArrayCacheDriver.php b/inc/Data/Driver/ArrayCacheDriver.php
index bb0cd310..8e74c9a5 100644
--- a/inc/Data/Driver/ArrayCacheDriver.php
+++ b/inc/Data/Driver/ArrayCacheDriver.php
@@ -1,20 +1,20 @@
 <?php
 namespace Vichan\Data\Driver;
 
-defined('TINYBOARD') or exit;
 
+defined('TINYBOARD') or exit;
 
 /**
  * A simple process-wide PHP array.
  */
 class ArrayCacheDriver implements CacheDriver {
-	private static array $inner = [];
+	private static $inner = [];
 
-	public function get(string $key): mixed {
+	public function get(string $key) {
 		return isset(self::$inner[$key]) ? self::$inner[$key] : null;
 	}
 
-	public function set(string $key, mixed $value, mixed $expires = false): void {
+	public function set(string $key, $value, $expires = false): void {
 		self::$inner[$key] = $value;
 	}
 
diff --git a/inc/Data/Driver/CacheDriver.php b/inc/Data/Driver/CacheDriver.php
index 083ed652..e35232a4 100644
--- a/inc/Data/Driver/CacheDriver.php
+++ b/inc/Data/Driver/CacheDriver.php
@@ -5,34 +5,34 @@ defined('TINYBOARD') or exit;
 
 
 interface CacheDriver {
-	/**
-	 * Get the value of associated with the key.
-	 *
-	 * @param string $key The key of the value.
-	 * @return mixed|null The value associated with the key, or null if there is none.
-	 */
-	public function get(string $key): mixed;
+        /**
+         * Get the value of associated with the key.
+         *
+         * @param string $key The key of the value.
+         * @return mixed|null The value associated with the key, or null if there is none.
+         */
+        public function get(string $key);
 
-	/**
-	 * Set a key-value pair.
-	 *
-	 * @param string $key The key.
-	 * @param mixed $value The value.
-	 * @param int|false $expires After how many seconds the pair will expire. Use false or ignore this parameter to keep
-	 *                           the value until it gets evicted to make space for more items. Some drivers will always
-	 *                           ignore this parameter and store the pair until it's removed.
-	 */
-	public function set(string $key, mixed $value, mixed $expires = false): void;
+        /**
+         * Set a key-value pair.
+         *
+         * @param string $key The key.
+         * @param mixed $value The value.
+         * @param int|false $expires After how many seconds the pair will expire. Use false or ignore this parameter to keep
+         *                           the value until it gets evicted to make space for more items. Some drivers will always
+         *                           ignore this parameter and store the pair until it's removed.
+         */
+        public function set(string $key, $value, $expires = false);
 
-	/**
-	 * Delete a key-value pair.
-	 *
-	 * @param string $key The key.
-	 */
-	public function delete(string $key): void;
+        /**
+         * Delete a key-value pair.
+         *
+         * @param string $key The key.
+         */
+        public function delete(string $key);
 
-	/**
-	 * Delete all the key-value pairs.
-	 */
-	public function flush(): void;
+        /**
+         * Delete all the key-value pairs.
+         */
+        public function flush();
 }