diff --git a/src/wizard/setup.finalize.test.ts b/src/wizard/setup.finalize.test.ts
index da10fcb3547c..ae88d80a7769 100644
--- a/src/wizard/setup.finalize.test.ts
+++ b/src/wizard/setup.finalize.test.ts
@@ -179,7 +179,8 @@ function createWebSearchProviderEntry(
 
 function expectFirstOnboardingInstallPlanCallOmitsToken() {
   const [firstArg] =
-    (buildGatewayInstallPlan.mock.calls.at(0) as [Record<string, unknown>] | undefined) ?? [];
+    (buildGatewayInstallPlan.mock.calls[0] as unknown as [Record<string, unknown>] | undefined) ??
+    [];
   if (!firstArg) {
     throw new Error("expected first onboarding install plan call");
   }