diff --git a/src/Asset.php b/src/Asset.php
index 81afc51..196f87f 100644
--- a/src/Asset.php
+++ b/src/Asset.php
@@ -93,7 +93,7 @@ public function getMetadata()
      * which is a value of any type other than a resource.
      * @since 5.4.0
      */
-    public function jsonSerialize()
+    public function jsonSerialize(): mixed
     {
         return [
             'value' => $this->getValue(),
diff --git a/src/AssetType.php b/src/AssetType.php
index 384a89b..6694ae5 100644
--- a/src/AssetType.php
+++ b/src/AssetType.php
@@ -75,7 +75,7 @@ private function stableSort(&$array, $cmp_function = 'strcmp')
             return;
         }
         // Split the array in half
-        $halfway = count($array) / 2;
+        $halfway = (int)(count($array) / 2);
         $array1 = array_slice($array, 0, $halfway);
         $array2 = array_slice($array, $halfway);
         // Recurse to sort the two halves
@@ -141,7 +141,7 @@ public function getValues() : array
      * which is a value of any type other than a resource.
      * @since 5.4.0
      */
-    public function jsonSerialize()
+    public function jsonSerialize(): mixed
     {
         return array_map(function (Asset $asset) {
             return $asset->jsonSerialize();