diff --git a/src/agents/context.lookup.test.ts b/src/agents/context.lookup.test.ts
index 884f83ef9ae..d0329b7f64a 100644
--- a/src/agents/context.lookup.test.ts
+++ b/src/agents/context.lookup.test.ts
@@ -60,9 +60,10 @@ describe("lookupContextTokens", () => {
     }));
 
     const { lookupContextTokens } = await import("./context.js");
-    await new Promise((resolve) => setTimeout(resolve, 0));
-    expect(lookupContextTokens("gpt-5.4")).toBe(1_050_000);
-    expect(lookupContextTokens("gpt-5.4-pro")).toBe(1_050_000);
+    await vi.waitFor(() => {
+      expect(lookupContextTokens("gpt-5.4")).toBe(1_050_000);
+      expect(lookupContextTokens("gpt-5.4-pro")).toBe(1_050_000);
+    });
   });
 
   it("does not skip eager warmup when --profile is followed by -- terminator", async () => {