diff --git a/docs/testing.md b/docs/testing.md
index 4aec82a6a..c773bdba3 100644
--- a/docs/testing.md
+++ b/docs/testing.md
@@ -224,7 +224,7 @@ final class MyClass
     {
     }
 
-    public function insertCustomer(array $customer): int
+    public function calculateSomething(): void
     {
         $now = $this->clock->now();