diff --git a/.flowconfig b/.flowconfig
index c83ba41c9..dd5aeef88 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -22,6 +22,10 @@ emoji=true
 all=true
 include_warnings=true
 module.name_mapper='flipper' -> '<PROJECT_ROOT>/src/index.js'
+module.file_ext=.js
+module.file_ext=.jsx
+module.file_ext=.json
+module.file_ext=.mjs
 module.file_ext=.tsx
 module.name_mapper.extension='tsx' -> 'any'
 module.name_mapper.extension='ts' -> 'any'
diff --git a/src/App.js b/src/App.js
index f810b0471..d78b8ae21 100644
--- a/src/App.js
+++ b/src/App.js
@@ -9,6 +9,7 @@ import React from 'react';
 import {FlexColumn, FlexRow} from 'flipper';
 import {connect} from 'react-redux';
 import WelcomeScreen from './chrome/WelcomeScreen.js';
+// $FlowFixMe T47375728
 import TitleBar from './chrome/TitleBar.tsx';
 import MainSidebar from './chrome/MainSidebar.js';
 import BugReporterDialog from './chrome/BugReporterDialog.js';
diff --git a/src/chrome/__tests__/TitleBar.electron.js b/src/chrome/__tests__/TitleBar.electron.js
index 60817f86d..5bb6441c2 100644
--- a/src/chrome/__tests__/TitleBar.electron.js
+++ b/src/chrome/__tests__/TitleBar.electron.js
@@ -5,6 +5,7 @@
  * @format
  */
 
+// $FlowFixMe T47375728
 import TitleBar from '../TitleBar.tsx';
 import renderer from 'react-test-renderer';
 import reducers from '../../reducers/index.js';
diff --git a/src/utils/CertificateProvider.js b/src/utils/CertificateProvider.js
index f571a9f76..ccd180d0e 100644
--- a/src/utils/CertificateProvider.js
+++ b/src/utils/CertificateProvider.js
@@ -21,6 +21,7 @@ import iosUtil from '../fb-stubs/iOSContainerUtility';
 import {reportPlatformFailures} from './metrics';
 import {getAdbClient} from './adbClient';
 import * as androidUtil from './androidContainerUtility';
+// $FlowFixMe T47375728
 import dateFormat from 'dateformat';
 const writeFile = promisify(fs.writeFile);
 const exists = promisify(fs.exists);
diff --git a/src/utils/__tests__/Idler.node.js b/src/utils/__tests__/Idler.node.js
index ef57429a0..2f4b44067 100644
--- a/src/utils/__tests__/Idler.node.js
+++ b/src/utils/__tests__/Idler.node.js
@@ -17,6 +17,7 @@ test('Idler should interrupt', async () => {
       }
       await idler.idle();
     }
+    // $FlowFixMe T47375728
     fail('Idler should have thrown an error');
   } catch (e) {
     expect(i).toEqual(100);
diff --git a/src/utils/reduxDevToolsConfig.js b/src/utils/reduxDevToolsConfig.js
index 1ca88309e..c858eed58 100644
--- a/src/utils/reduxDevToolsConfig.js
+++ b/src/utils/reduxDevToolsConfig.js
@@ -5,6 +5,7 @@
  * @format
  */
 
+// $FlowFixMe T47375728
 export const stateSanitizer = state => {
   let sanitizedState = state;
   if (state.connections) {