diff --git a/src/infra/outbound/outbound-send-service.test.ts b/src/infra/outbound/outbound-send-service.test.ts
index 1f952993db9..40f588f443e 100644
--- a/src/infra/outbound/outbound-send-service.test.ts
+++ b/src/infra/outbound/outbound-send-service.test.ts
@@ -126,7 +126,7 @@ function expectSingleCallFirstArg(
   label = "mock first argument",
 ): Record<string, unknown> {
   expect(mock.mock.calls).toHaveLength(1);
-  const [firstArg] = mock.mock.calls.at(0) ?? [];
+  const [firstArg] = mock.mock.calls[0] ?? [];
   return requireRecord(firstArg, label);
 }