diff --git a/src/Composer/Repository/ArrayRepository.php b/src/Composer/Repository/ArrayRepository.php
index 90cf938f4210..f1d0da780714 100644
--- a/src/Composer/Repository/ArrayRepository.php
+++ b/src/Composer/Repository/ArrayRepository.php
@@ -283,6 +283,7 @@ public function getPackages()
      *
      * @return int Number of packages
      */
+    #[ReturnTypeWillChange]
     public function count()
     {
         if (null === $this->packages) {