diff --git a/CHANGELOG.md b/CHANGELOG.md
index f73b697..e056c55 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,10 @@
 CHANGELOG
 =========
 
+6.12.1
+-----
+* Fixed a json serializable return datatype deprecation that occurred when running on PHP 8.1
+
 6.12.0
 -----
 * Added OpenStack resource
diff --git a/src/Entity/AbstractEntity.php b/src/Entity/AbstractEntity.php
index 4617436..9064aa8 100644
--- a/src/Entity/AbstractEntity.php
+++ b/src/Entity/AbstractEntity.php
@@ -2,9 +2,7 @@
 
 namespace Transip\Api\Library\Entity;
 
-use JsonSerializable;
-
-class AbstractEntity implements JsonSerializable
+class AbstractEntity implements \JsonSerializable
 {
     public function __construct(array $valueArray = [])
     {
@@ -15,6 +13,14 @@ public function __construct(array $valueArray = [])
         }
     }
 
+    /**
+     * This method returns data that can be serialized by json_encode()
+     * natively.
+     *
+     * @return mixed
+     * @link http://php.net/manual/en/jsonserializable.jsonserialize.php
+     */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return get_object_vars($this);
diff --git a/src/TransipAPI.php b/src/TransipAPI.php
index 186d6ee..37cc950 100644
--- a/src/TransipAPI.php
+++ b/src/TransipAPI.php
@@ -64,7 +64,7 @@
 class TransipAPI
 {
     public const TRANSIP_API_ENDPOINT = "https://api.transip.nl/v6";
-    public const TRANSIP_API_LIBRARY_VERSION = "6.12.0";
+    public const TRANSIP_API_LIBRARY_VERSION = "6.12.1";
     public const TRANSIP_API_DEMO_TOKEN = "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImp0aSI6ImN3MiFSbDU2eDNoUnkjelM4YmdOIn0.eyJpc3MiOiJhcGkudHJhbnNpcC5ubCIsImF1ZCI6ImFwaS50cmFuc2lwLm5sIiwianRpIjoiY3cyIVJsNTZ4M2hSeSN6UzhiZ04iLCJpYXQiOjE1ODIyMDE1NTAsIm5iZiI6MTU4MjIwMTU1MCwiZXhwIjoyMTE4NzQ1NTUwLCJjaWQiOiI2MDQ0OSIsInJvIjpmYWxzZSwiZ2siOmZhbHNlLCJrdiI6dHJ1ZX0.fYBWV4O5WPXxGuWG-vcrFWqmRHBm9yp0PHiYh_oAWxWxCaZX2Rf6WJfc13AxEeZ67-lY0TA2kSaOCp0PggBb_MGj73t4cH8gdwDJzANVxkiPL1Saqiw2NgZ3IHASJnisUWNnZp8HnrhLLe5ficvb1D9WOUOItmFC2ZgfGObNhlL2y-AMNLT4X7oNgrNTGm-mespo0jD_qH9dK5_evSzS3K8o03gu6p19jxfsnIh8TIVRvNdluYC2wo4qDl5EW5BEZ8OSuJ121ncOT1oRpzXB0cVZ9e5_UVAEr9X3f26_Eomg52-PjrgcRJ_jPIUYbrlo06KjjX2h0fzMr21ZE023Gw";
 
     /**