diff --git a/packages/cli/src/commands/doctor/healthchecks/androidHomeEnvVariable.js b/packages/cli/src/commands/doctor/healthchecks/androidHomeEnvVariable.ts
similarity index 62%
rename from packages/cli/src/commands/doctor/healthchecks/androidHomeEnvVariable.js
rename to packages/cli/src/commands/doctor/healthchecks/androidHomeEnvVariable.ts
index 2135ced6b..cbb865060 100644
--- a/packages/cli/src/commands/doctor/healthchecks/androidHomeEnvVariable.js
+++ b/packages/cli/src/commands/doctor/healthchecks/androidHomeEnvVariable.ts
@@ -1,9 +1,7 @@
-// @flow
 import chalk from 'chalk';
-import Ora from 'ora';
-// $FlowFixMe - converted to TS
+import {Ora} from 'ora';
 import {logManualInstallation} from './common';
-import type {HealthCheckInterface} from '../types';
+import {HealthCheckInterface} from '../types';
 
 // List of answers on how to set `ANDROID_HOME` for each platform
 const URLS = {
@@ -14,20 +12,24 @@ const URLS = {
 
 const label = 'ANDROID_HOME';
 
+// Force the options for the platform to avoid providing a link
+// for `ANDROID_HOME` for every platform NodeJS supports
+const platform = process.platform as 'darwin' | 'win32' | 'linux';
+
 const message = `Read more about how to set the ${label} at ${chalk.dim(
-  URLS[process.platform],
+  URLS[platform],
 )}.`;
 
-export default ({
+export default {
   label,
   getDiagnostics: async () => ({
     needsToBeFixed: !process.env.ANDROID_HOME && message,
   }),
-  runAutomaticFix: async ({loader}: {loader: typeof Ora}) => {
+  runAutomaticFix: async ({loader}: {loader: Ora}) => {
     loader.info();
 
     logManualInstallation({
       message,
     });
   },
-}: HealthCheckInterface);
+} as HealthCheckInterface;
diff --git a/packages/cli/src/commands/doctor/healthchecks/androidNDK.js b/packages/cli/src/commands/doctor/healthchecks/androidNDK.ts
similarity index 77%
rename from packages/cli/src/commands/doctor/healthchecks/androidNDK.js
rename to packages/cli/src/commands/doctor/healthchecks/androidNDK.ts
index 3550d1aa3..fe5de0bc9 100644
--- a/packages/cli/src/commands/doctor/healthchecks/androidNDK.js
+++ b/packages/cli/src/commands/doctor/healthchecks/androidNDK.ts
@@ -1,15 +1,11 @@
-// @flow
 import chalk from 'chalk';
-import Ora from 'ora';
-// $FlowFixMe - converted to TS
+import {Ora} from 'ora';
 import {logManualInstallation} from './common';
-// $FlowFixMe - converted to TS
 import versionRanges from '../versionRanges';
-// $FlowFixMe - converted to TS
 import {doesSoftwareNeedToBeFixed} from '../checkInstallation';
-import type {EnvironmentInfo, HealthCheckInterface} from '../types';
+import {EnvironmentInfo, HealthCheckInterface} from '../types';
 
-export default ({
+export default {
   label: 'Android NDK',
   getDiagnostics: async ({SDKs}: EnvironmentInfo) => ({
     needsToBeFixed: doesSoftwareNeedToBeFixed({
@@ -21,8 +17,8 @@ export default ({
     loader,
     environmentInfo,
   }: {
-    loader: typeof Ora,
-    environmentInfo: EnvironmentInfo,
+    loader: Ora;
+    environmentInfo: EnvironmentInfo;
   }) => {
     const version = environmentInfo.SDKs['Android SDK']['Android NDK'];
     const isNDKInstalled = version !== 'Not Found';
@@ -42,4 +38,4 @@ export default ({
       url: 'https://developer.android.com/ndk/downloads',
     });
   },
-}: HealthCheckInterface);
+} as HealthCheckInterface;
diff --git a/packages/cli/src/commands/doctor/healthchecks/cocoaPods.js b/packages/cli/src/commands/doctor/healthchecks/cocoaPods.ts
similarity index 64%
rename from packages/cli/src/commands/doctor/healthchecks/cocoaPods.js
rename to packages/cli/src/commands/doctor/healthchecks/cocoaPods.ts
index 92874f0c1..81e362bad 100644
--- a/packages/cli/src/commands/doctor/healthchecks/cocoaPods.js
+++ b/packages/cli/src/commands/doctor/healthchecks/cocoaPods.ts
@@ -1,14 +1,11 @@
-// @flow
-// $FlowFixMe - converted to TS
 import {checkSoftwareInstalled} from '../checkInstallation';
-// $FlowFixMe - converted to TS
 import {installCocoaPods} from '../../../tools/installPods';
-import {type HealthCheckInterface} from '../types';
+import {HealthCheckInterface} from '../types';
 
-export default ({
+export default {
   label: 'CocoaPods',
   getDiagnostics: async () => ({
     needsToBeFixed: await checkSoftwareInstalled('pod'),
   }),
   runAutomaticFix: async ({loader}) => await installCocoaPods(loader),
-}: HealthCheckInterface);
+} as HealthCheckInterface;
diff --git a/packages/cli/src/commands/doctor/healthchecks/index.js b/packages/cli/src/commands/doctor/healthchecks/index.js
index c95ddf644..9b94f942b 100644
--- a/packages/cli/src/commands/doctor/healthchecks/index.js
+++ b/packages/cli/src/commands/doctor/healthchecks/index.js
@@ -2,10 +2,13 @@
 import nodeJS from './nodeJS';
 import {yarn, npm} from './packageManagers';
 import watchman from './watchman';
+// $FlowFixMe - converted to TS
 import androidHomeEnvVariable from './androidHomeEnvVariable';
 import androidSDK from './androidSDK';
+// $FlowFixMe - converted to TS
 import androidNDK from './androidNDK';
 import xcode from './xcode';
+// $FlowFixMe - converted to TS
 import cocoaPods from './cocoaPods';
 import iosDeploy from './iosDeploy';
 
diff --git a/packages/cli/src/commands/doctor/types.ts b/packages/cli/src/commands/doctor/types.ts
index 9c5a5e7a8..3489827e0 100644
--- a/packages/cli/src/commands/doctor/types.ts
+++ b/packages/cli/src/commands/doctor/types.ts
@@ -1,4 +1,4 @@
-import Ora from 'ora';
+import {Ora} from 'ora';
 
 export type EnvironmentInfo = {
   System: {
@@ -72,7 +72,7 @@ export type HealthCheckInterface = {
     environmentInfo: EnvironmentInfo,
   ) => Promise<{version?: string; needsToBeFixed: boolean | string}>;
   runAutomaticFix: (args: {
-    loader: typeof Ora;
+    loader: Ora;
     environmentInfo: EnvironmentInfo;
   }) => Promise<void> | void;
 };