diff --git a/bun.lock b/bun.lock
index 0bd6d3deaa..f44103e550 100644
--- a/bun.lock
+++ b/bun.lock
@@ -339,7 +339,7 @@
         "@hyperframes/studio-server": "workspace:*",
         "@mcp-b/global": "^5.0.1",
         "@phosphor-icons/react": "^2.1.10",
-        "@tanstack/react-virtual": "^3.14.6",
+        "@tanstack/react-virtual": "^3.14.13",
         "bpm-detective": "^2.0.5",
         "cn": "0.2.4",
         "dockview-react": "8.3.1",
@@ -1170,9 +1170,9 @@
 
     "@tailwindcss/vite": ["@tailwindcss/vite@4.3.3", "", { "dependencies": { "@tailwindcss/node": "4.3.3", "@tailwindcss/oxide": "4.3.3", "tailwindcss": "4.3.3" }, "peerDependencies": { "vite": "^5.2.0 || ^6 || ^7 || ^8" } }, "sha512-yYU8cogLeSh/ms2jh8Fj7jaba/EWa7Ja6GoUqYZaraEuCI5YS6ms6ObZgjjedm+jm6XZjdNRWBpPP6Z86oOxcw=="],
 
-    "@tanstack/react-virtual": ["@tanstack/react-virtual@3.14.6", "", { "dependencies": { "@tanstack/virtual-core": "3.17.4" }, "peerDependencies": { "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0", "react-dom": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0" } }, "sha512-4+Uq8m0/gzO4kMCHUEpTtGX1RnONK0C+g88b2ltwPMWUBiaVarBuWKoPJaz7gj1cKCVRAdyu+U8GcKhwCc2beA=="],
+    "@tanstack/react-virtual": ["@tanstack/react-virtual@3.14.13", "", { "dependencies": { "@tanstack/virtual-core": "3.17.11" }, "peerDependencies": { "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0", "react-dom": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0" } }, "sha512-JbDTAwtzZ99aOeCrAfW5EsE5KSq5RWh6Af2dtFwyLIIk48Ja7vm6n4axu/43T3vfjFnEGJalxJ1wyYjSQD6bSg=="],
 
-    "@tanstack/virtual-core": ["@tanstack/virtual-core@3.17.4", "", {}, "sha512-nGm5KteqxasUdThLc2izl6dHUqLv0LQj7Nuyo5gYalTPf/U8a9ermvsl7reT+6ioBW1l8WfpP/mcU338nLXpqw=="],
+    "@tanstack/virtual-core": ["@tanstack/virtual-core@3.17.11", "", {}, "sha512-+ILjvtHup6Y2hzQ6YzwMgX1Q+oQpxEGOXCEsCNaPoIP0VxMbizIBTmYTDtkerkIQS8/CbP1BRuyt8V/8BCsy1g=="],
 
     "@tootallnate/once": ["@tootallnate/once@2.0.1", "", {}, "sha512-HqmEUIGRJ5fSXchkVgR5F7qn48bDBzv0kWj/Kfu5e6uci4UlEeng4331LnBkWffb++Ei3FOVLxo8JJWMFBDMeQ=="],
 
diff --git a/packages/studio-server/src/history/pruneHistories.test.ts b/packages/studio-server/src/history/pruneHistories.test.ts
index ccd83cce21..47705c0054 100644
--- a/packages/studio-server/src/history/pruneHistories.test.ts
+++ b/packages/studio-server/src/history/pruneHistories.test.ts
@@ -31,6 +31,8 @@ function tempDir(prefix: string): string {
 }
 
 const DAY_MS = 24 * 60 * 60 * 1000;
+// Date.now() rounds down to the millisecond; a file written in that millisecond can carry a later mtime.
+const pastKeepWindow = () => Date.now() + 1 + KEEP_GONE_PROJECT_HISTORY_MS;
 
 async function projectWithHistory(
   historyRoot: string,
@@ -105,7 +107,7 @@ describe("pruneGoneProjectHistories", () => {
     expect(await prunedIds(historyRoot, { ...elsewhere, now: Date.now() + 13 * DAY_MS })).toEqual(
       [],
     );
-    expect(await prunedIds(historyRoot, { ...elsewhere, now: Date.now() + 14 * DAY_MS })).toEqual([
+    expect(await prunedIds(historyRoot, { ...elsewhere, now: pastKeepWindow() })).toEqual([
       gone.id,
     ]);
   });
@@ -178,7 +180,7 @@ describe("pruneGoneProjectHistories", () => {
 
       chmodSync(locked, 0o000);
       try {
-        const later = Date.now() + KEEP_GONE_PROJECT_HISTORY_MS;
+        const later = pastKeepWindow();
         const onError = (error: unknown) => errors.push(error);
         expect(await prunedIds(historyRoot, { now: later, onError })).toEqual([gone.id]);
       } finally {
@@ -206,7 +208,7 @@ describe("pruneGoneProjectHistories", () => {
     rmSync(join(mountPoint.projectDir, ".hyperframes"), { recursive: true, force: true });
     rmSync(dirname(deleted.projectDir), { recursive: true, force: true });
 
-    const later = Date.now() + KEEP_GONE_PROJECT_HISTORY_MS;
+    const later = pastKeepWindow();
     expect(await prunedIds(historyRoot, { tempDir: historyRoot, now: later })).toEqual([
       deleted.id,
     ]);
@@ -227,7 +229,7 @@ describe("pruneGoneProjectHistories", () => {
     rmSync(folderGone.projectDir, { recursive: true, force: true });
     rmSync(dirname(parentGone.projectDir), { recursive: true, force: true });
 
-    const later = Date.now() + KEEP_GONE_PROJECT_HISTORY_MS;
+    const later = pastKeepWindow();
     expect(await prunedIds(historyRoot, { tempDir: historyRoot, now: later })).toEqual([
       emptied.id,
     ]);
diff --git a/packages/studio/package.json b/packages/studio/package.json
index 607909fa4d..597d4af3bb 100644
--- a/packages/studio/package.json
+++ b/packages/studio/package.json
@@ -103,7 +103,7 @@
     "@hyperframes/studio-server": "workspace:*",
     "@mcp-b/global": "^5.0.1",
     "@phosphor-icons/react": "^2.1.10",
-    "@tanstack/react-virtual": "^3.14.6",
+    "@tanstack/react-virtual": "^3.14.13",
     "bpm-detective": "^2.0.5",
     "cn": "0.2.4",
     "dockview-react": "8.3.1",
diff --git a/packages/studio/src/player/components/useTimelineVirtualRows.test.tsx b/packages/studio/src/player/components/useTimelineVirtualRows.test.tsx
index c0be0a8ea5..e4d8256cef 100644
--- a/packages/studio/src/player/components/useTimelineVirtualRows.test.tsx
+++ b/packages/studio/src/player/components/useTimelineVirtualRows.test.tsx
@@ -2,7 +2,13 @@
 
 import React, { act } from "react";
 import { createRoot } from "react-dom/client";
-import { afterAll, afterEach, beforeAll, describe, expect, it } from "vitest";
+import {
+  elementScroll,
+  observeElementOffset,
+  observeElementRect,
+  Virtualizer,
+} from "@tanstack/react-virtual";
+import { afterAll, afterEach, beforeAll, describe, expect, it, vi } from "vitest";
 import { createTimelineRowGeometry, RULER_H, TRACKS_TOP_PAD } from "./timelineLayout";
 import { extractTimelineVirtualRowRange, useTimelineVirtualRows } from "./useTimelineVirtualRows";
 import type { TimelineScrollViewportSnapshot } from "./useTimelineScrollViewport";
@@ -203,4 +209,27 @@ describe("useTimelineVirtualRows", () => {
     expect(rows.some((row) => row.index === 500)).toBe(false);
     act(() => root.unmount());
   });
+
+  // A scroll-end timer left running fires into the torn-down test window ("window is not defined").
+  it("gets no virtualizer change after unmount from a scroll just before it", async () => {
+    const scroll = createScrollElement(0);
+    const onChange = vi.fn();
+    const virtualizer = new Virtualizer<HTMLDivElement, Element>({
+      count: 100,
+      getScrollElement: () => scroll,
+      estimateSize: () => 48,
+      scrollToFn: elementScroll,
+      observeElementRect,
+      observeElementOffset,
+      onChange,
+    });
+    const unmount = virtualizer._didMount();
+    virtualizer._willUpdate();
+    scroll.dispatchEvent(new Event("scroll"));
+    unmount();
+    onChange.mockClear();
+
+    await new Promise((settle) => setTimeout(settle, 200));
+    expect(onChange).not.toHaveBeenCalled();
+  });
 });