diff --git a/packages/producer/src/regression-harness-parse.test.ts b/packages/producer/src/regression-harness-parse.test.ts
index ae7ba39337..a27505a451 100644
--- a/packages/producer/src/regression-harness-parse.test.ts
+++ b/packages/producer/src/regression-harness-parse.test.ts
@@ -6,7 +6,10 @@
 // must move together.
 
 import { describe, expect, it } from "bun:test";
-import { parseArgs } from "./regression-harness.js";
+import { mkdtempSync, mkdirSync, readFileSync, rmSync, statSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { createRegressionTempRoot, parseArgs } from "./regression-harness.js";
 
 // parseArgs reads from index 2 onwards (node + script name are argv[0..1]).
 const withProgram = (rest: string[]): string[] => ["node", "regression-harness.ts", ...rest];
@@ -52,3 +55,29 @@ describe("parseArgs() — --exclude-tags", () => {
     expect(opts.excludeTags).toEqual([]);
   });
 });
+
+describe("regression temporary roots", () => {
+  it("isolates repeated suite runs and preserves the old predictable directory", () => {
+    const parent = mkdtempSync(join(tmpdir(), "hf-root-test-"));
+    try {
+      const legacy = join(parent, "hyperframes-tests", "same-suite");
+      mkdirSync(legacy, { recursive: true });
+      const sentinel = join(legacy, "keep.txt");
+      writeFileSync(sentinel, "unrelated data");
+      const first = createRegressionTempRoot("same-suite", parent);
+      const second = createRegressionTempRoot("same-suite", parent);
+      expect(first).not.toBe(second);
+      expect(first).not.toBe(legacy);
+      if (process.platform !== "win32") {
+        expect(statSync(first).mode & 0o777).toBe(0o700);
+        expect(statSync(second).mode & 0o777).toBe(0o700);
+      }
+      expect(readFileSync(sentinel, "utf8")).toBe("unrelated data");
+      rmSync(first, { recursive: true, force: true });
+      expect(statSync(second).isDirectory()).toBe(true);
+      expect(readFileSync(sentinel, "utf8")).toBe("unrelated data");
+    } finally {
+      rmSync(parent, { recursive: true, force: true });
+    }
+  });
+});
diff --git a/packages/producer/src/regression-harness.ts b/packages/producer/src/regression-harness.ts
index f18fc16ec5..57eee5c9da 100644
--- a/packages/producer/src/regression-harness.ts
+++ b/packages/producer/src/regression-harness.ts
@@ -963,6 +963,10 @@ export async function checkStreamDurationParity(
 
 // ── Test Execution ───────────────────────────────────────────────────────────
 
+export function createRegressionTempRoot(suiteId: string, parent: string = tmpdir()): string {
+  return mkdtempSync(join(parent, `hyperframes-test-${suiteId}-`));
+}
+
 async function runTestSuite(
   suite: TestSuite,
   options: {
@@ -971,17 +975,7 @@ async function runTestSuite(
     mode: HarnessMode;
   },
 ): Promise<TestResult> {
-  // Use predictable temp location: /tmp/hyperframes-tests/{test-id}/
-  const testsRoot = join(tmpdir(), "hyperframes-tests");
-  if (!existsSync(testsRoot)) {
-    mkdirSync(testsRoot, { recursive: true });
-  }
-
-  const tempRoot = join(testsRoot, suite.id);
-  if (existsSync(tempRoot)) {
-    rmSync(tempRoot, { recursive: true, force: true });
-  }
-  mkdirSync(tempRoot, { recursive: true });
+  const tempRoot = createRegressionTempRoot(suite.id);
 
   const tempDownloadDir = join(tempRoot, "downloads");
   const outputFormat = suite.meta.renderConfig.format ?? "mp4";
diff --git a/packages/producer/src/services/render/stages/captureStreamingStage.test.ts b/packages/producer/src/services/render/stages/captureStreamingStage.test.ts
index 80ed36203b..66dca5fbc3 100644
--- a/packages/producer/src/services/render/stages/captureStreamingStage.test.ts
+++ b/packages/producer/src/services/render/stages/captureStreamingStage.test.ts
@@ -1,5 +1,12 @@
 // fallow-ignore-file code-duplication
-import { describe, expect, it, mock } from "bun:test";
+import { afterAll, describe, expect, it, mock } from "bun:test";
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+const fixtureRoot = mkdtempSync(join(tmpdir(), "hf-stage-test-"));
+const framesDir = join(fixtureRoot, "frames");
+afterAll(() => rmSync(fixtureRoot, { recursive: true, force: true }));
 import { getCaptureStageBrowserConsole } from "../captureStageError.js";
 import { createCapturePlan } from "../capturePlan.js";
 
@@ -191,7 +198,7 @@ function createInput(cfg: MinimalEngineConfig) {
       addPreHeadScript: () => {},
     },
     workDir: "/tmp/hf-test-work",
-    framesDir: "/tmp/hf-test-frames",
+    framesDir: framesDir,
     videoOnlyPath: "/tmp/hf-test-video-only.mp4",
     job: {
       id: "streaming-config-test",
@@ -487,7 +494,7 @@ describe("runCaptureStage", () => {
     const cfg = { forceScreenshot: false, ffmpegStreamingTimeout: 3_600_000 };
     const probeSession = await createCaptureSession(
       "http://127.0.0.1:4173",
-      "/tmp/hf-test-frames",
+      framesDir,
       {},
       null,
       cfg,
@@ -599,7 +606,7 @@ describe("runCaptureHdrStage", () => {
         },
         projectDir: "/tmp/hf-test-project",
         compiledDir: "/tmp/hf-test-compiled",
-        framesDir: "/tmp/hf-test-frames",
+        framesDir: framesDir,
         videoOnlyPath: "/tmp/hf-test-video-only.mp4",
         width: 1920,
         height: 1080,
diff --git a/packages/producer/src/services/render/stages/probeStage.test.ts b/packages/producer/src/services/render/stages/probeStage.test.ts
index 79721a7d91..b6ee9e5ed3 100644
--- a/packages/producer/src/services/render/stages/probeStage.test.ts
+++ b/packages/producer/src/services/render/stages/probeStage.test.ts
@@ -1,4 +1,10 @@
-import { describe, expect, it, mock } from "bun:test";
+import { afterAll, describe, expect, it, mock } from "bun:test";
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+const workDir = mkdtempSync(join(tmpdir(), "hf-stage-test-"));
+afterAll(() => rmSync(workDir, { recursive: true, force: true }));
 import { createHash } from "node:crypto";
 import {
   hasAutoStartVideos,
@@ -239,7 +245,7 @@ function makeProbeInput(overrides: {
 
   return {
     projectDir: "/tmp/hf-probe-test-project",
-    workDir: "/tmp/hf-probe-test-work",
+    workDir: workDir,
     job: {
       id: "probe-test",
       config: { fps: { num: 30, den: 1 }, quality: "standard" },