diff --git a/src/cron/isolated-agent/run.test-harness.ts b/src/cron/isolated-agent/run.test-harness.ts
index 6a1fa1c3dff..b708ec47bfd 100644
--- a/src/cron/isolated-agent/run.test-harness.ts
+++ b/src/cron/isolated-agent/run.test-harness.ts
@@ -64,7 +64,6 @@ vi.mock("../../agents/skills/refresh.js", () => ({
 }));
 
 vi.mock("../../agents/workspace.js", () => ({
-  DEFAULT_IDENTITY_FILENAME: "IDENTITY.md",
   ensureAgentWorkspace: vi.fn().mockResolvedValue({ dir: "/tmp/workspace" }),
 }));
 
@@ -172,12 +171,18 @@ vi.mock("../../logger.js", () => ({
   logWarn: (...args: unknown[]) => logWarnMock(...args),
 }));
 
-vi.mock("../../security/external-content.js", () => ({
-  buildSafeExternalPrompt: vi.fn().mockReturnValue("safe prompt"),
-  detectSuspiciousPatterns: vi.fn().mockReturnValue([]),
-  getHookType: vi.fn().mockReturnValue("unknown"),
-  isExternalHookSession: vi.fn().mockReturnValue(false),
-}));
+vi.mock("../../security/external-content.js", async () => {
+  const actual = await vi.importActual<typeof import("../../security/external-content.js")>(
+    "../../security/external-content.js",
+  );
+  return {
+    ...actual,
+    buildSafeExternalPrompt: vi.fn().mockReturnValue("safe prompt"),
+    detectSuspiciousPatterns: vi.fn().mockReturnValue([]),
+    getHookType: vi.fn().mockReturnValue("unknown"),
+    isExternalHookSession: vi.fn().mockReturnValue(false),
+  };
+});
 
 vi.mock("../delivery.js", () => ({
   resolveCronDeliveryPlan: resolveCronDeliveryPlanMock,