diff --git a/Libraries/Alert/Alert.js b/Libraries/Alert/Alert.js
index 40666f70e35076..6598175c0825d3 100644
--- a/Libraries/Alert/Alert.js
+++ b/Libraries/Alert/Alert.js
@@ -16,6 +16,7 @@ const NativeModules = require('NativeModules');
 const Platform = require('Platform');
 
 import type { AlertType, AlertButtonStyle } from 'AlertIOS';
+import type { Fbt } from 'fbt';
 
 export type Buttons = Array<{
   text?: string,
@@ -79,8 +80,8 @@ type Options = {
 class Alert {
 
   static alert(
-    title: ?string,
-    message?: ?string,
+    title: ?string | ?Fbt,
+    message?: ?string | ?Fbt,
     buttons?: Buttons,
     options?: Options,
     type?: AlertType,
@@ -104,8 +105,8 @@ class Alert {
 class AlertAndroid {
 
   static alert(
-    title: ?string,
-    message?: ?string,
+    title: ?string | ?Fbt,
+    message?: ?string | ?Fbt,
     buttons?: Buttons,
     options?: Options,
   ): void {
diff --git a/Libraries/Alert/AlertIOS.js b/Libraries/Alert/AlertIOS.js
index 375a4db56c96a2..933df8512a3b95 100644
--- a/Libraries/Alert/AlertIOS.js
+++ b/Libraries/Alert/AlertIOS.js
@@ -12,7 +12,9 @@
  */
 'use strict';
 
-var RCTAlertManager = require('NativeModules').AlertManager;
+const RCTAlertManager = require('NativeModules').AlertManager;
+
+import type { Fbt } from 'fbt';
 
 /**
  * An Alert button type
@@ -133,8 +135,8 @@ class AlertIOS {
    * );
    */
   static alert(
-    title: ?string,
-    message?: ?string,
+    title: ?string | ?Fbt,
+    message?: ?string | ?Fbt,
     callbackOrButtons?: ?(() => void) | ButtonsArray,
     type?: AlertType,
   ): void {
@@ -192,8 +194,8 @@ class AlertIOS {
    * );
    */
   static prompt(
-    title: ?string,
-    message?: ?string,
+    title: ?string | ?Fbt,
+    message?: ?string | ?Fbt,
     callbackOrButtons?: ?((text: string) => void) | ButtonsArray,
     type?: ?AlertType = 'plain-text',
     defaultValue?: string,