diff --git a/src/renderer/store/TimelineSpace/Contents.ts b/src/renderer/store/TimelineSpace/Contents.ts
index d2312ad6..a30206bb 100644
--- a/src/renderer/store/TimelineSpace/Contents.ts
+++ b/src/renderer/store/TimelineSpace/Contents.ts
@@ -1,6 +1,6 @@
 import SideBar, { SideBarModuleState } from './Contents/SideBar'
 import Home, { HomeState } from './Contents/Home'
-import Notifications from './Contents/Notifications'
+import Notifications, { NotificationsState } from './Contents/Notifications'
 import Favourites from './Contents/Favourites'
 import Local, { LocalState } from './Contents/Local'
 import Public, { PublicState } from './Contents/Public'
@@ -17,6 +17,7 @@ export interface ContentsState {}
 export interface ContentsModuleState extends ContentsState {
   SideBar: SideBarModuleState,
   Home: HomeState,
+  Notifications: NotificationsState,
   Local: LocalState,
   Public: PublicState
 }
diff --git a/src/renderer/store/TimelineSpace/Contents/Notifications.js b/src/renderer/store/TimelineSpace/Contents/Notifications.js
deleted file mode 100644
index ae1ba0e7..00000000
--- a/src/renderer/store/TimelineSpace/Contents/Notifications.js
+++ /dev/null
@@ -1,102 +0,0 @@
-import { ipcRenderer } from 'electron'
-import Mastodon from 'megalodon'
-
-const Notifications = {
-  namespaced: true,
-  state: {
-    lazyLoading: false,
-    heading: true,
-    notifications: [],
-    unreadNotifications: [],
-    filter: ''
-  },
-  mutations: {
-    changeLazyLoading (state, value) {
-      state.lazyLoading = value
-    },
-    changeHeading (state, value) {
-      state.heading = value
-    },
-    appendNotifications (state, notification) {
-      if (state.heading) {
-        state.notifications = [notification].concat(state.notifications)
-      } else {
-        state.unreadNotifications = [notification].concat(state.unreadNotifications)
-      }
-    },
-    updateNotifications (state, notifications) {
-      state.notifications = notifications
-    },
-    mergeNotifications (state) {
-      state.notifications = state.unreadNotifications.slice(0, 80).concat(state.notifications)
-      state.unreadNotifications = []
-    },
-    insertNotifications (state, notifications) {
-      state.notifications = state.notifications.concat(notifications)
-    },
-    updateToot (state, message) {
-      state.notifications = state.notifications.map((notification) => {
-        // I want to update toot only mention.
-        // Because Toot component don't use status information when other patterns.
-        if (notification.type === 'mention' && notification.status.id === message.id) {
-          const status = {
-            status: message
-          }
-          return Object.assign(notification, status)
-        } else {
-          return notification
-        }
-      })
-    },
-    clearNotifications (state) {
-      state.notifications = []
-    },
-    archiveNotifications (state) {
-      state.notifications = state.notifications.slice(0, 30)
-    },
-    changeFilter (state, filter) {
-      state.filter = filter
-    }
-  },
-  actions: {
-    fetchNotifications ({ commit, rootState }) {
-      const client = new Mastodon(
-        rootState.TimelineSpace.account.accessToken,
-        rootState.TimelineSpace.account.baseURL + '/api/v1'
-      )
-      return client.get('/notifications', { limit: 30 })
-        .then(res => {
-          commit('updateNotifications', res.data)
-          return res.data
-        })
-    },
-    lazyFetchNotifications ({ state, commit, rootState }, last) {
-      if (last === undefined || last === null) {
-        return Promise.resolve(null)
-      }
-      if (state.lazyLoading) {
-        return Promise.resolve(null)
-      }
-      commit('changeLazyLoading', true)
-      const client = new Mastodon(
-        rootState.TimelineSpace.account.accessToken,
-        rootState.TimelineSpace.account.baseURL + '/api/v1'
-      )
-      return client.get('/notifications', { max_id: last.id, limit: 30 })
-        .then(res => {
-          commit('changeLazyLoading', false)
-          commit('insertNotifications', res.data)
-          return res.data
-        })
-        .catch(err => {
-          commit('changeLazyLoading', false)
-          throw err
-        })
-    },
-    resetBadge () {
-      ipcRenderer.send('reset-badge')
-    }
-  }
-}
-
-export default Notifications
diff --git a/src/renderer/store/TimelineSpace/Contents/Notifications.ts b/src/renderer/store/TimelineSpace/Contents/Notifications.ts
new file mode 100644
index 00000000..53847c2c
--- /dev/null
+++ b/src/renderer/store/TimelineSpace/Contents/Notifications.ts
@@ -0,0 +1,125 @@
+import { ipcRenderer } from 'electron'
+import Mastodon, { Notification, Status, Response } from 'megalodon'
+import { Module, MutationTree, ActionTree } from 'vuex'
+import { RootState } from '@/store'
+
+export interface NotificationsState {
+  lazyLoading: boolean,
+  heading: boolean,
+  notifications: Array<Notification>,
+  unreadNotifications: Array<Notification>,
+  filter: string
+}
+
+const state = (): NotificationsState => ({
+  lazyLoading: false,
+  heading: true,
+  notifications: [],
+  unreadNotifications: [],
+  filter: ''
+})
+
+export const MUTATION_TYPES = {
+  CHANGE_LAZY_LOADING: 'changeLazyLoading',
+  CHANGE_HEADING: 'changeHeading',
+  APPEND_NOTIFICATIONS: 'appendNotifications',
+  UPDATE_NOTIFICATIONS: 'updateNotifications',
+  MERGE_NOTIFICATIONS: 'mergeNotifications',
+  INSERT_NOTIFICATIONS: 'insertNotifications',
+  UPDATE_TOOT: 'updateToot',
+  CLEAR_NOTIFICATIONS: 'clearNotifications',
+  ARCHIVE_NOTIFICATIONS: 'archiveNotifications',
+  CHANGE_FILTER: 'changeFilter'
+}
+
+const mutations: MutationTree<NotificationsState> = {
+  [MUTATION_TYPES.CHANGE_LAZY_LOADING]: (state, value: boolean) => {
+    state.lazyLoading = value
+  },
+  [MUTATION_TYPES.CHANGE_HEADING]: (state, value: boolean) => {
+    state.heading = value
+  },
+  [MUTATION_TYPES.APPEND_NOTIFICATIONS]: (state, notification: Notification) => {
+    if (state.heading) {
+      state.notifications = [notification].concat(state.notifications)
+    } else {
+      state.unreadNotifications = [notification].concat(state.unreadNotifications)
+    }
+  },
+  [MUTATION_TYPES.UPDATE_NOTIFICATIONS]: (state, notifications: Array<Notification>) => {
+    state.notifications = notifications
+  },
+  [MUTATION_TYPES.MERGE_NOTIFICATIONS]: (state) => {
+    state.notifications = state.unreadNotifications.slice(0, 80).concat(state.notifications)
+    state.unreadNotifications = []
+  },
+  [MUTATION_TYPES.INSERT_NOTIFICATIONS]: (state, notifications: Array<Notification>) => {
+    state.notifications = state.notifications.concat(notifications)
+  },
+  [MUTATION_TYPES.UPDATE_TOOT]: (state, message: Status) => {
+    state.notifications = state.notifications.map((notification) => {
+      // I want to update toot only mention.
+      // Because Toot component don't use status information when other patterns.
+      if (notification.status !== null && notification.status.id === message.id) {
+        const status = {
+          status: message
+        }
+        return Object.assign(notification, status)
+      } else {
+        return notification
+      }
+    })
+  },
+  [MUTATION_TYPES.CLEAR_NOTIFICATIONS]: (state) => {
+    state.notifications = []
+  },
+  [MUTATION_TYPES.ARCHIVE_NOTIFICATIONS]: (state) => {
+    state.notifications = state.notifications.slice(0, 30)
+  },
+  [MUTATION_TYPES.CHANGE_FILTER]: (state, filter: string) => {
+    state.filter = filter
+  }
+}
+
+const actions: ActionTree<NotificationsState, RootState> = {
+  fetchNotifications: async ({ commit, rootState }): Promise<Array<Notification>> => {
+    const client = new Mastodon(
+      rootState.TimelineSpace.account.accessToken!,
+      rootState.TimelineSpace.account.baseURL + '/api/v1'
+    )
+    const res: Response<Array<Notification>> = await client.get<Array<Notification>>('/notifications', { limit: 30 })
+
+    commit(MUTATION_TYPES.UPDATE_NOTIFICATIONS, res.data)
+    return res.data
+  },
+  lazyFetchNotifications: ({ state, commit, rootState }, lastNotification: Notification): Promise<Array<Notification> | null> => {
+    if (state.lazyLoading) {
+      return Promise.resolve(null)
+    }
+    commit(MUTATION_TYPES.CHANGE_LAZY_LOADING, true)
+    const client = new Mastodon(
+      rootState.TimelineSpace.account.accessToken!,
+      rootState.TimelineSpace.account.baseURL + '/api/v1'
+    )
+    return client.get<Array<Notification>>('/notifications', { max_id: lastNotification.id, limit: 30 })
+      .then(res => {
+        commit(MUTATION_TYPES.INSERT_NOTIFICATIONS, res.data)
+        return res.data
+      })
+      .finally(() => {
+        commit(MUTATION_TYPES.CHANGE_LAZY_LOADING, false)
+      })
+  },
+  resetBadge: () => {
+    ipcRenderer.send('reset-badge')
+  }
+}
+
+const Notifications: Module<NotificationsState, RootState> = {
+  namespaced: true,
+  state: state,
+  mutations: mutations,
+  actions: actions
+}
+
+export default Notifications