diff --git a/tests/e2e/Client.php b/tests/e2e/Client.php
index 16e3466f78..c86ebc5951 100644
--- a/tests/e2e/Client.php
+++ b/tests/e2e/Client.php
@@ -122,7 +122,7 @@ class Client
      * @param string $endpoint
      * @return self $this
      */
-    public function setEndpoint($endpoint): self
+    public function setEndpoint(string $endpoint): self
     {
         $this->endpoint = $endpoint;