diff --git a/tests/runner-e2e/controller-outage.test.ts b/tests/runner-e2e/controller-outage.test.ts
index d366c3f1096..f95778b617c 100644
--- a/tests/runner-e2e/controller-outage.test.ts
+++ b/tests/runner-e2e/controller-outage.test.ts
@@ -88,10 +88,14 @@ describe("controller outage qualification", () => {
     expect(f.input.start).not.toHaveBeenCalled();
   });
 
-  it.each([-1, 300001, 0.5, NaN, Infinity, "300000", null])("rejects invalid duration %s before signaling", holdMs => {
+  it.each([-1, 600001, 0.5, NaN, Infinity, "300000", null])("rejects invalid duration %s before signaling", holdMs => {
     expect(() => parseControllerOutage({ signal: "SIGKILL", holdMs })).toThrow();
   });
-  it.each(["", "-1", "1e3", "NaN", " 1000", "300001"])("rejects invalid environment duration %s", value => {
+  it("accepts chaos holds up to ten minutes", () => {
+    expect(parseControllerOutage({ signal: "SIGKILL", holdMs: 360_000 })).toEqual({ signal: "SIGKILL", holdMs: 360_000 });
+    expect(parseControllerOutage({ signal: "SIGTERM", holdMs: 600_000 })).toEqual({ signal: "SIGTERM", holdMs: 600_000 });
+  });
+  it.each(["", "-1", "1e3", "NaN", " 1000", "600001"])("rejects invalid environment duration %s", value => {
     expect(() => configuredControllerOutage({ PAPERCLIP_RUNNER_E2E_CONTROLLER_OUTAGE_MS: value })).toThrow();
   });
   it("accepts the five-minute contract without extending the runner grace", () => {
diff --git a/tests/runner-e2e/controller-outage.ts b/tests/runner-e2e/controller-outage.ts
index 758f80a8c33..2f07b834089 100644
--- a/tests/runner-e2e/controller-outage.ts
+++ b/tests/runner-e2e/controller-outage.ts
@@ -26,11 +26,21 @@ export interface ControllerOutageReceipt extends ControllerOutage {
   recoveryProgress?: Partial<ControllerRecoveryReceipt>;
 }
 
+/**
+ * Longest controller outage a harness may inject. Ten minutes lets chaos
+ * holds pass Daytona's sandbox auto-stop and the 7-minute runner reconnect
+ * grace. The recover-controller receipt check below still requires readiness
+ * inside that grace, so this does not loosen the qualification contract.
+ */
+export const MAX_CONTROLLER_OUTAGE_MS = 600_000;
+
 export function parseControllerOutage(value: unknown): ControllerOutage {
   if (!value || typeof value !== "object" || Array.isArray(value)) throw new Error("Invalid controller outage");
   const { signal, holdMs } = value as Record<string, unknown>;
   if ((signal !== "SIGTERM" && signal !== "SIGKILL") || !Number.isSafeInteger(holdMs)
-    || Number(holdMs) < 0 || Number(holdMs) > 300_000) throw new Error("Controller outage requires SIGTERM/SIGKILL and 0..300000 integer milliseconds");
+    || Number(holdMs) < 0 || Number(holdMs) > MAX_CONTROLLER_OUTAGE_MS) {
+    throw new Error(`Controller outage requires SIGTERM/SIGKILL and 0..${MAX_CONTROLLER_OUTAGE_MS} integer milliseconds`);
+  }
   return { signal, holdMs: Number(holdMs) };
 }
 
diff --git a/tests/runner-e2e/server-restart-request.test.ts b/tests/runner-e2e/server-restart-request.test.ts
index bfec299ead9..958c9face87 100644
--- a/tests/runner-e2e/server-restart-request.test.ts
+++ b/tests/runner-e2e/server-restart-request.test.ts
@@ -62,7 +62,7 @@ it("rejects cache replacement for unselected, local and legacy cells", async ()
 
 it.each([
   { controllerOutage: { signal: "SIGKILL", holdMs: 125_000 }, discardControllerCache: false },
-  { controllerOutage: { signal: "SIGKILL", holdMs: 300_001 }, discardControllerCache: true },
+  { controllerOutage: { signal: "SIGKILL", holdMs: 600_001 }, discardControllerCache: true },
   { controllerOutage: { signal: "SIGKILL", holdMs: 125_000 }, discardControllerCache: true, preserveRunner: {} },
   { controllerOutage: { signal: "SIGKILL", holdMs: 125_000 }, discardControllerCache: true, crashAfterResult: {} },
   { recoveryBinding: {} },