diff --git a/src/agents/pi-tools.schema.test.ts b/src/agents/pi-tools.schema.test.ts
index 8999510b3c7..acd7ebb5ea2 100644
--- a/src/agents/pi-tools.schema.test.ts
+++ b/src/agents/pi-tools.schema.test.ts
@@ -428,7 +428,7 @@ describe("normalizeToolParameters", () => {
     );
 
     expect(streamCalls).toBe(2);
-    const executeCall = execute.mock.calls.at(0);
+    const executeCall = execute.mock.calls[0];
     expect(executeCall?.[0]).toBe("call-null-args");
     expect(executeCall?.[1]).toEqual({});
     expect(executeCall?.[2]).toBeUndefined();