diff --git a/CHANGELOG.md b/CHANGELOG.md
index 42f464d765..6da584d58f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Unreleased
 
--
+- [added] `messaging.ApsAlert` type now supports subtitle in its payload.
 
 # v6.1.0
 
diff --git a/src/index.d.ts b/src/index.d.ts
index 87e097092c..8c30e32d6f 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -426,11 +426,14 @@ declare namespace admin.messaging {
 
   type ApsAlert = {
     title?: string;
+    subtitle?: string;
     body?: string;
     locKey?: string;
     locArgs?: string[];
     titleLocKey?: string;
     titleLocArgs?: string[];
+    subtitleLocKey?: string;
+    subtitleLocArgs?: string[];
     actionLocKey?: string;
     launchImage?: string;
   };
diff --git a/src/messaging/messaging.ts b/src/messaging/messaging.ts
index eef402ddab..fbcf17cdad 100644
--- a/src/messaging/messaging.ts
+++ b/src/messaging/messaging.ts
@@ -180,11 +180,14 @@ export interface Aps {
 
 export interface ApsAlert {
   title?: string;
+  subtitle?: string;
   body?: string;
   locKey?: string;
   locArgs?: string[];
   titleLocKey?: string;
   titleLocArgs?: string[];
+  subtitleLocKey?: string;
+  subtitleLocArgs?: string[];
   actionLocKey?: string;
   launchImage?: string;
 }
@@ -357,12 +360,20 @@ function validateApsAlert(alert: string | ApsAlert) {
       MessagingClientErrorCode.INVALID_PAYLOAD,
       'apns.payload.aps.alert.titleLocKey is required when specifying titleLocArgs');
   }
+  if (validator.isNonEmptyArray(apsAlert.subtitleLocArgs) &&
+  !validator.isNonEmptyString(apsAlert.subtitleLocKey)) {
+    throw new FirebaseMessagingError(
+      MessagingClientErrorCode.INVALID_PAYLOAD,
+      'apns.payload.aps.alert.subtitleLocKey is required when specifying subtitleLocArgs');
+  }
 
   const propertyMappings = {
     locKey: 'loc-key',
     locArgs: 'loc-args',
     titleLocKey: 'title-loc-key',
     titleLocArgs: 'title-loc-args',
+    subtitleLocKey: 'subtitle-loc-key',
+    subtitleLocArgs: 'subtitle-loc-args',
     actionLocKey: 'action-loc-key',
     launchImage: 'launch-image',
   };
diff --git a/test/unit/messaging/messaging.spec.ts b/test/unit/messaging/messaging.spec.ts
index f01986b0b7..648dad3a4b 100644
--- a/test/unit/messaging/messaging.spec.ts
+++ b/test/unit/messaging/messaging.spec.ts
@@ -1733,6 +1733,24 @@ describe('Messaging', () => {
       }).to.throw('titleLocKey is required when specifying titleLocArgs');
     });
 
+    it('should throw given apns subtitleLocArgs without subtitleLocKey', () => {
+      const message: Message = {
+        condition: 'topic-name',
+        apns: {
+          payload: {
+            aps: {
+              alert: {
+                subtitleLocArgs: ['foo'],
+              },
+            },
+          },
+        },
+      };
+      expect(() => {
+        messaging.send(message);
+      }).to.throw('subtitleLocKey is required when specifying subtitleLocArgs');
+    });
+
     it('should throw given apns locArgs without locKey', () => {
       const message: Message = {
         condition: 'topic-name',
@@ -2260,11 +2278,17 @@ describe('Messaging', () => {
             payload: {
               aps: {
                 alert: {
+                  title: 'title',
+                  subtitle: 'subtitle',
+                  body: 'body',
                   titleLocKey: 'title.loc.key',
                   titleLocArgs: ['arg1', 'arg2'],
+                  subtitleLocKey: 'subtitle.loc.key',
+                  subtitleLocArgs: ['arg1', 'arg2'],
                   locKey: 'body.loc.key',
                   locArgs: ['arg1', 'arg2'],
                   actionLocKey: 'action.loc.key',
+                  launchImage: 'image',
                 },
                 badge: 42,
                 sound: 'test.sound',
@@ -2287,11 +2311,17 @@ describe('Messaging', () => {
             payload: {
               aps: {
                 'alert': {
+                  'title': 'title',
+                  'subtitle': 'subtitle',
+                  'body': 'body',
                   'title-loc-key': 'title.loc.key',
                   'title-loc-args': ['arg1', 'arg2'],
+                  'subtitle-loc-key': 'subtitle.loc.key',
+                  'subtitle-loc-args': ['arg1', 'arg2'],
                   'loc-key': 'body.loc.key',
                   'loc-args': ['arg1', 'arg2'],
                   'action-loc-key': 'action.loc.key',
+                  'launch-image': 'image',
                 },
                 'badge': 42,
                 'sound': 'test.sound',