diff --git a/src/BitPayKeyUtils/KeyHelper/Key.php b/src/BitPayKeyUtils/KeyHelper/Key.php
index b0ec71e..73ce20b 100644
--- a/src/BitPayKeyUtils/KeyHelper/Key.php
+++ b/src/BitPayKeyUtils/KeyHelper/Key.php
@@ -101,6 +101,34 @@ public function unserialize($data)
             ) = unserialize($data);
     }
 
+    /**
+     * @return array
+     */
+    public function __serialize(): array
+    {
+        return [
+            $this->id,
+            $this->x,
+            $this->y,
+            $this->hex,
+            $this->dec,
+        ];
+    }
+
+    /**
+     * @param array $data
+     */
+    public function __unserialize(array $data): void
+    {
+        list(
+            $this->id,
+            $this->x,
+            $this->y,
+            $this->hex,
+            $this->dec
+            ) = $data;
+    }
+
     /**
      * @return boolean
      */