diff --git a/tests/setup/floating-toolbar-subscriptions-loader-hooks.mjs b/tests/setup/floating-toolbar-subscriptions-loader-hooks.mjs
new file mode 100644
index 000000000..dc3648445
--- /dev/null
+++ b/tests/setup/floating-toolbar-subscriptions-loader-hooks.mjs
@@ -0,0 +1,103 @@
+import { readFile } from 'node:fs/promises'
+import { fileURLToPath } from 'node:url'
+
+const floatingToolbarStubs = new Map([
+  ['../ConversationCard', 'test:subscription-conversation-card'],
+  ['../../content-script/selection-tools', 'test:subscription-selection-tools'],
+  ['../../utils', 'test:subscription-utils'],
+  ['react-draggable', 'test:subscription-draggable'],
+  ['react-i18next', 'test:subscription-i18n'],
+])
+
+const useConfigStubs = new Map([
+  ['../config/index.mjs', 'test:subscription-config'],
+  ['webextension-polyfill', 'test:subscription-browser'],
+])
+
+const sources = {
+  'test:subscription-conversation-card': `
+    export default function ConversationCard(props) {
+      globalThis.__FLOATING_SUBSCRIPTION_TEST__.onCloseBySession.set(props.session.id, props.onClose)
+      return null
+    }
+  `,
+  'test:subscription-selection-tools': 'export const config = {}',
+  'test:subscription-utils': `
+    export const getClientPosition = () => ({ x: 0, y: 0 })
+    export const isMobile = () => true
+    export const setElementPositionInViewport = (_container, x, y) => ({ x, y })
+  `,
+  'test:subscription-draggable': `
+    export default function Draggable(props) {
+      return props.children
+    }
+  `,
+  'test:subscription-i18n': 'export const useTranslation = () => ({ t: (value) => value })',
+  'test:subscription-config': `
+    export const defaultConfig = {
+      alwaysPinWindow: false,
+      themeMode: 'light',
+      activeSelectionTools: [],
+      customSelectionTools: [],
+    }
+    export const getUserConfig = async () => defaultConfig
+  `,
+  'test:subscription-browser': `
+    const state = globalThis.__FLOATING_SUBSCRIPTION_TEST__
+    export default {
+      storage: {
+        local: {
+          onChanged: {
+            addListener(listener) {
+              state.storageListeners.add(listener)
+            },
+            removeListener(listener) {
+              state.storageListeners.delete(listener)
+            },
+          },
+        },
+      },
+    }
+  `,
+}
+
+export async function resolve(specifier, context, nextResolve) {
+  if (context.parentURL?.endsWith('/src/components/FloatingToolbar/index.jsx')) {
+    if (specifier === '../../hooks/use-clamp-window-size') {
+      return nextResolve('../../hooks/use-clamp-window-size.mjs', context)
+    }
+
+    const stubUrl = floatingToolbarStubs.get(specifier)
+    if (stubUrl) return { url: stubUrl, shortCircuit: true }
+  }
+
+  if (context.parentURL?.endsWith('/src/hooks/use-config.mjs')) {
+    const stubUrl = useConfigStubs.get(specifier)
+    if (stubUrl) return { url: stubUrl, shortCircuit: true }
+  }
+
+  return nextResolve(specifier, context)
+}
+
+export async function load(url, context, nextLoad) {
+  if (url.startsWith('test:subscription-')) {
+    return {
+      shortCircuit: true,
+      format: 'module',
+      source: sources[url],
+    }
+  }
+
+  if (url.startsWith('file://') && url.endsWith('.jsx') && !url.includes('node_modules')) {
+    const source = await readFile(fileURLToPath(url), 'utf8')
+    const esbuild = await import('esbuild')
+    const result = await esbuild.transform(source, {
+      loader: 'jsx',
+      jsx: 'automatic',
+      jsxImportSource: 'preact',
+    })
+    return { shortCircuit: true, format: 'module', source: result.code }
+  }
+
+  return nextLoad(url, context)
+}
diff --git a/tests/unit/components/floating-toolbar-subscriptions.test.mjs b/tests/unit/components/floating-toolbar-subscriptions.test.mjs
new file mode 100644
index 000000000..44f587c9b
--- /dev/null
+++ b/tests/unit/components/floating-toolbar-subscriptions.test.mjs
@@ -0,0 +1,257 @@
+import assert from 'node:assert/strict'
+import { register } from 'node:module'
+import { cwd } from 'node:process'
+import { after, afterEach, before, test } from 'node:test'
+import { pathToFileURL } from 'node:url'
+import { JSDOM } from 'jsdom'
+import { h, render } from 'preact'
+import { act } from 'preact/test-utils'
+
+register(
+  './tests/setup/floating-toolbar-subscriptions-loader-hooks.mjs',
+  pathToFileURL(cwd() + '/').href,
+)
+
+let dom
+let FloatingToolbar
+const originalDescriptors = new Map()
+const globalNames = ['window', 'document', 'Node', 'HTMLElement']
+const toolbarContainers = new Set()
+
+const getCapture = (options) => (typeof options === 'boolean' ? options : Boolean(options?.capture))
+
+const createListenerTracker = () => {
+  const registrations = []
+  const matches = (registration, listener, options) =>
+    registration.listener === listener && registration.capture === getCapture(options)
+
+  return {
+    add(listener, options) {
+      if (registrations.some((registration) => matches(registration, listener, options))) return
+      registrations.push({ listener, capture: getCapture(options) })
+    },
+    remove(listener, options) {
+      const index = registrations.findIndex((registration) =>
+        matches(registration, listener, options),
+      )
+      if (index !== -1) registrations.splice(index, 1)
+    },
+    snapshot() {
+      return registrations.map((registration) => ({ ...registration }))
+    },
+    has(target) {
+      return registrations.some(
+        (registration) =>
+          registration.listener === target.listener && registration.capture === target.capture,
+      )
+    },
+    clear() {
+      registrations.length = 0
+    },
+    get size() {
+      return registrations.length
+    },
+  }
+}
+
+const resizeListeners = createListenerTracker()
+const selectionListeners = createListenerTracker()
+
+const waitFor = async (predicate, message) => {
+  for (let attempt = 0; attempt < 50; ++attempt) {
+    if (predicate()) return
+    await new Promise((resolve) => setTimeout(resolve, 0))
+  }
+  assert.fail(message)
+}
+
+const sameListenerRegistration = (left, right) =>
+  left.listener === right.listener && left.capture === right.capture
+
+const getNewListener = (listeners, previousListeners, label) => {
+  const addedListeners = listeners
+    .snapshot()
+    .filter(
+      (listener) =>
+        !previousListeners.some((previousListener) =>
+          sameListenerRegistration(listener, previousListener),
+        ),
+    )
+  assert.equal(addedListeners.length, 1, `expected one new ${label} listener`)
+  return addedListeners[0]
+}
+
+const getNewSetEntry = (entries, previousEntries, label) => {
+  const addedEntries = [...entries].filter((entry) => !previousEntries.has(entry))
+  assert.equal(addedEntries.length, 1, `expected one new ${label} listener`)
+  return addedEntries[0]
+}
+
+const createToolbar = async (id) => {
+  const state = globalThis.__FLOATING_SUBSCRIPTION_TEST__
+  const previousResizeListeners = resizeListeners.snapshot()
+  const previousSelectionListeners = selectionListeners.snapshot()
+  const previousStorageListeners = new Set(state.storageListeners)
+  const container = document.createElement('div')
+  document.body.append(container)
+  toolbarContainers.add(container)
+
+  await act(async () => {
+    render(
+      h(FloatingToolbar, {
+        session: { id },
+        selection: 'selected text',
+        container,
+        triggered: true,
+        closeable: true,
+        dockable: false,
+        prompt: 'prompt',
+      }),
+      container,
+    )
+    await Promise.resolve()
+    await Promise.resolve()
+  })
+
+  const getCloseCallback = () => globalThis.__FLOATING_SUBSCRIPTION_TEST__.onCloseBySession.get(id)
+  await waitFor(
+    () => typeof getCloseCallback() === 'function',
+    `close callback was not rendered for ${id}`,
+  )
+
+  const onClose = getCloseCallback()
+  return {
+    container,
+    listeners: {
+      resize: getNewListener(resizeListeners, previousResizeListeners, 'resize'),
+      selection: getNewListener(selectionListeners, previousSelectionListeners, 'selection'),
+      storage: getNewSetEntry(state.storageListeners, previousStorageListeners, 'storage'),
+    },
+    close: () => {
+      onClose()
+    },
+  }
+}
+
+before(async () => {
+  dom = new JSDOM('<!doctype html><html><body></body></html>', { url: 'https://example.com/' })
+
+  for (const name of globalNames) {
+    originalDescriptors.set(name, Object.getOwnPropertyDescriptor(globalThis, name))
+    Object.defineProperty(globalThis, name, {
+      configurable: true,
+      value: dom.window[name],
+    })
+  }
+
+  const originalWindowAddEventListener = window.addEventListener.bind(window)
+  const originalWindowRemoveEventListener = window.removeEventListener.bind(window)
+  window.addEventListener = (type, listener, options) => {
+    if (type === 'resize') resizeListeners.add(listener, options)
+    return originalWindowAddEventListener(type, listener, options)
+  }
+  window.removeEventListener = (type, listener, options) => {
+    if (type === 'resize') resizeListeners.remove(listener, options)
+    return originalWindowRemoveEventListener(type, listener, options)
+  }
+
+  const originalDocumentAddEventListener = document.addEventListener.bind(document)
+  const originalDocumentRemoveEventListener = document.removeEventListener.bind(document)
+  document.addEventListener = (type, listener, options) => {
+    if (type === 'selectionchange') selectionListeners.add(listener, options)
+    return originalDocumentAddEventListener(type, listener, options)
+  }
+  document.removeEventListener = (type, listener, options) => {
+    if (type === 'selectionchange') selectionListeners.remove(listener, options)
+    return originalDocumentRemoveEventListener(type, listener, options)
+  }
+
+  globalThis.__FLOATING_SUBSCRIPTION_TEST__ = {
+    onCloseBySession: new Map(),
+    storageListeners: new Set(),
+  }
+  ;({ default: FloatingToolbar } = await import(
+    '../../../src/components/FloatingToolbar/index.jsx'
+  ))
+})
+
+afterEach(() => {
+  act(() => {
+    for (const container of toolbarContainers) render(null, container)
+  })
+  for (const container of toolbarContainers) container.remove()
+  toolbarContainers.clear()
+  document.body.replaceChildren()
+  resizeListeners.clear()
+  selectionListeners.clear()
+  globalThis.__FLOATING_SUBSCRIPTION_TEST__.onCloseBySession.clear()
+  globalThis.__FLOATING_SUBSCRIPTION_TEST__.storageListeners.clear()
+})
+
+after(() => {
+  dom.window.close()
+  delete globalThis.__FLOATING_SUBSCRIPTION_TEST__
+
+  for (const [name, descriptor] of originalDescriptors) {
+    if (descriptor) Object.defineProperty(globalThis, name, descriptor)
+    else delete globalThis[name]
+  }
+})
+
+test('listener tracking keeps registrations when capture does not match', () => {
+  const listener = () => {}
+  window.addEventListener('resize', listener, { capture: true })
+  try {
+    window.removeEventListener('resize', listener, { capture: false })
+    assert.equal(resizeListeners.size, 1)
+  } finally {
+    window.removeEventListener('resize', listener, { capture: true })
+  }
+
+  assert.equal(resizeListeners.size, 0)
+})
+
+test('closing a floating toolbar removes its real hook subscriptions', async () => {
+  const state = globalThis.__FLOATING_SUBSCRIPTION_TEST__
+  const toolbar = await createToolbar('one')
+
+  assert.equal(resizeListeners.size, 1)
+  assert.equal(selectionListeners.size, 1)
+  assert.equal(state.storageListeners.size, 1)
+  assert.equal(toolbar.listeners.resize.capture, false)
+  assert.equal(toolbar.listeners.selection.capture, false)
+
+  act(() => toolbar.close())
+
+  assert.equal(toolbar.container.isConnected, false)
+  assert.equal(resizeListeners.size, 0)
+  assert.equal(selectionListeners.size, 0)
+  assert.equal(state.storageListeners.size, 0)
+})
+
+test('closing one toolbar leaves another toolbar subscriptions active', async () => {
+  const state = globalThis.__FLOATING_SUBSCRIPTION_TEST__
+  const first = await createToolbar('first')
+  const second = await createToolbar('second')
+
+  assert.equal(resizeListeners.size, 2)
+  assert.equal(selectionListeners.size, 2)
+  assert.equal(state.storageListeners.size, 2)
+
+  act(() => first.close())
+
+  assert.equal(first.container.isConnected, false)
+  assert.equal(second.container.isConnected, true)
+  assert.equal(resizeListeners.has(first.listeners.resize), false)
+  assert.equal(selectionListeners.has(first.listeners.selection), false)
+  assert.equal(state.storageListeners.has(first.listeners.storage), false)
+  assert.equal(resizeListeners.has(second.listeners.resize), true)
+  assert.equal(selectionListeners.has(second.listeners.selection), true)
+  assert.equal(state.storageListeners.has(second.listeners.storage), true)
+
+  act(() => second.close())
+
+  assert.equal(resizeListeners.size, 0)
+  assert.equal(selectionListeners.size, 0)
+  assert.equal(state.storageListeners.size, 0)
+})