diff --git a/tests/HttpStatusTest.php b/tests/HttpStatusTest.php
index 7d3d0e9..aefbe3e 100644
--- a/tests/HttpStatusTest.php
+++ b/tests/HttpStatusTest.php
@@ -287,7 +287,7 @@ public function ianaCodesReasonPhrasesProvider(): array
         return $ianaCodesReasonPhrases;
     }
 
-    public function testChangeExceptionMessage()
+    public function testChangeExceptionMessage(): void
     {
         $message   = 'new message';
         $exception = new Exception\NotFoundException($message);