diff --git a/packages/redrob/test/cli/run/run-process.test.ts b/packages/redrob/test/cli/run/run-process.test.ts
index cb318b5fea..f72728da03 100644
--- a/packages/redrob/test/cli/run/run-process.test.ts
+++ b/packages/redrob/test/cli/run/run-process.test.ts
@@ -6,7 +6,7 @@
 import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { reply } from "../../lib/llm-server"
-import { cliIt } from "../../lib/cli-process"
+import { cliIt, slowPlatform } from "../../lib/cli-process"
 
 describe("redrob run (non-interactive subprocess)", () => {
   // Happy path: prompt completes, output reaches stdout, process exits 0.
@@ -73,10 +73,12 @@ describe("redrob run (non-interactive subprocess)", () => {
       Effect.gen(function* () {
         const result = yield* redrob.run("say hi", {
           model: "test/nonexistent-model",
-          timeoutMs: 15_000,
+          timeoutMs: slowPlatform(15_000),
         })
         expect(result.exitCode).not.toBe(0)
-        expect(result.durationMs).toBeLessThan(15_000)
+        /* Scaled WITH the bound: the claim is that it exits promptly rather than being killed, and a
+           duration assertion pinned to a base figure while the bound moves tests the wrong thing. */
+        expect(result.durationMs).toBeLessThan(slowPlatform(15_000))
       }),
     60_000,
   )
@@ -96,7 +98,7 @@ describe("redrob run (non-interactive subprocess)", () => {
         )
         yield* llm.fail("upstream provider exploded mid-stream")
         yield* llm.text("recovered")
-        const result = yield* redrob.run("trigger midstream error", { timeoutMs: 30_000 })
+        const result = yield* redrob.run("trigger midstream error", { timeoutMs: slowPlatform(30_000) })
         expect(result.exitCode).toBe(0)
         expect(result.stdout).toBe("partial response\nrecovered\n")
         expect(result.stderr).not.toContain("upstream provider exploded mid-stream")
diff --git a/packages/redrob/test/lib/cli-process.ts b/packages/redrob/test/lib/cli-process.ts
index e9d141e2d7..80537c6d0e 100644
--- a/packages/redrob/test/lib/cli-process.ts
+++ b/packages/redrob/test/lib/cli-process.ts
@@ -63,6 +63,16 @@ const CHILD_TIMEOUT_MS = 30_000 * SLOW_PLATFORM_FACTOR
 const READY_TIMEOUT_MS = 15_000 * SLOW_PLATFORM_FACTOR
 const TEST_TIMEOUT_MS = CHILD_TIMEOUT_MS * 2
 
+/**
+ * A test's own bound, scaled for the slow platform.
+ *
+ * For the call sites that pass an explicit `timeoutMs` rather than taking the default -- those bypass the
+ * allowance entirely, which is how the first version of this fix left the very test that was flaking still
+ * pinned to thirty seconds. Write `slowPlatform(30_000)` and the intent stays readable while the platform
+ * correction is applied for you.
+ */
+export const slowPlatform = (ms: number) => ms * SLOW_PLATFORM_FACTOR
+
 export const testModelID = "test/test-model"
 
 // Wrap a Bun subprocess pipe (or any ReadableStream<Uint8Array>) as a Stream.
@@ -572,9 +582,16 @@ export const cliIt = {
     (process.platform === "win32" ? test : test.concurrent)(
       name,
       () => Effect.runPromise(Effect.scoped(withCliFixture(body))),
-      // Bun's timeout includes spawn-gate wait, so it must stay above the child timeout or a queued
-      // concurrent CLI test expires while holding no permit. Derived from it rather than restated, which
-      // is what let the two drift apart.
-      opts ?? TEST_TIMEOUT_MS,
+      /*
+        A caller's own number is a FLOOR, not a ceiling.
+
+        Bun's timeout includes spawn-gate wait, so it must stay above the child timeout or a queued test
+        expires while holding no permit -- and that failure reads as a slow command rather than as a
+        mis-tuned harness. Dozens of call sites pass `60_000`, which was comfortably above the old fixed
+        30s child bound and is BELOW the Windows one, so honouring them literally would have reintroduced
+        exactly the drift these constants exist to prevent. Clamped here rather than edited at every call
+        site: the invariant then holds by construction instead of by everyone remembering it.
+      */
+      typeof opts === "number" ? Math.max(opts, TEST_TIMEOUT_MS) : (opts ?? TEST_TIMEOUT_MS),
     ),
 }