diff --git a/src/data/hooks.ts b/src/data/hooks.ts
index 00a71d8dd4..f8ad29bed8 100644
--- a/src/data/hooks.ts
+++ b/src/data/hooks.ts
@@ -1,4 +1,5 @@
 import { useSelector } from 'react-redux';
+import { RootState } from '../store';
 
 // eslint-disable-next-line import/prefer-default-export
-export const useContextId = () => useSelector(state => state.courseHome.courseId);
+export const useContextId = () => useSelector<RootState>(state => state.courseHome.courseId);
diff --git a/src/index.jsx b/src/index.jsx
index af7a153096..76e4eed375 100755
--- a/src/index.jsx
+++ b/src/index.jsx
@@ -26,7 +26,7 @@ import { TabContainer } from './tab-page';
 
 import { fetchDatesTab, fetchOutlineTab, fetchProgressTab } from './course-home/data';
 import { fetchCourse } from './courseware/data';
-import initializeStore from './store';
+import { store } from './store';
 import NoticesProvider from './generic/notices';
 import PathFixesProvider from './generic/path-fixes';
 import LiveTab from './course-home/live-tab/LiveTab';
@@ -38,7 +38,7 @@ import PageNotFound from './generic/PageNotFound';
 
 subscribe(APP_READY, () => {
   ReactDOM.render(
-    <AppProvider store={initializeStore()}>
+    <AppProvider store={store}>
       <Helmet>
         <link rel="shortcut icon" href={getConfig().FAVICON_URL} type="image/x-icon" />
       </Helmet>
diff --git a/src/store.js b/src/store.ts
similarity index 92%
rename from src/store.js
rename to src/store.ts
index 9343b0d24a..32a77cdafe 100644
--- a/src/store.js
+++ b/src/store.ts
@@ -29,3 +29,7 @@ export default function initializeStore() {
     }),
   });
 }
+
+export const store = initializeStore();
+
+export type RootState = ReturnType<typeof store.getState>;