diff --git a/tests/e2e/tab-strip-active-dock.spec.ts b/tests/e2e/tab-strip-active-dock.spec.ts
index 0a3dbe09363..eaacd2ef4dc 100644
--- a/tests/e2e/tab-strip-active-dock.spec.ts
+++ b/tests/e2e/tab-strip-active-dock.spec.ts
@@ -15,6 +15,13 @@ const STRIP = '.terminal-tab-strip'
 
 type DockSample = { scrollLeft: number; activeLeft: number; activeRight: number }
 
+declare global {
+  // oxlint-disable-next-line typescript-eslint/consistent-type-definitions -- declaration merging requires interface
+  interface Window {
+    __tabStripDockSamples?: DockSample[]
+  }
+}
+
 function slotSelector(tabId: string): string {
   return `${STRIP} > [data-tab-strip-slot="${tabId}"]`
 }
@@ -120,7 +127,7 @@ test.describe('Tab strip active-tab dock', () => {
           requestAnimationFrame(sample)
         }
         requestAnimationFrame(sample)
-        Reflect.set(window, '__tabStripDockSamples', samples)
+        window.__tabStripDockSamples = samples
       },
       { strip: STRIP, slot: slotSelector(lastTabId) }
     )
@@ -141,9 +148,7 @@ test.describe('Tab strip active-tab dock', () => {
     const finalScrollLeft = await strip.evaluate((el) => el.scrollLeft)
     expect(finalScrollLeft).toBeGreaterThan(0)
     const view = await readSlotViewportSpan(orcaPage, lastTabId)
-    const samples: DockSample[] = await orcaPage.evaluate(() =>
-      Reflect.get(window, '__tabStripDockSamples')
-    )
+    const samples = await orcaPage.evaluate(() => window.__tabStripDockSamples ?? [])
     expect(samples.length).toBeGreaterThan(0)
     for (const sample of samples) {
       // One jump from the docked position to the reveal; any value in between is visible scrolling.