diff --git a/packages/firebase_messaging/CHANGELOG.md b/packages/firebase_messaging/CHANGELOG.md
index 3bdb90a57bc2..4bf3c6fa0199 100644
--- a/packages/firebase_messaging/CHANGELOG.md
+++ b/packages/firebase_messaging/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 5.1.0
+
+* Changed the return type of `subscribeToTopic` and `unsubscribeFromTopic` to
+  `Future<void>`.
+
 ## 5.0.6
 
 * Additional integration tests.
diff --git a/packages/firebase_messaging/android/src/main/java/io/flutter/plugins/firebasemessaging/FirebaseMessagingPlugin.java b/packages/firebase_messaging/android/src/main/java/io/flutter/plugins/firebasemessaging/FirebaseMessagingPlugin.java
index 11befeba8642..4ab56e01d299 100644
--- a/packages/firebase_messaging/android/src/main/java/io/flutter/plugins/firebasemessaging/FirebaseMessagingPlugin.java
+++ b/packages/firebase_messaging/android/src/main/java/io/flutter/plugins/firebasemessaging/FirebaseMessagingPlugin.java
@@ -119,12 +119,38 @@ public void onComplete(@NonNull Task<InstanceIdResult> task) {
       result.success(null);
     } else if ("subscribeToTopic".equals(call.method)) {
       String topic = call.arguments();
-      FirebaseMessaging.getInstance().subscribeToTopic(topic);
-      result.success(null);
+      FirebaseMessaging.getInstance()
+          .subscribeToTopic(topic)
+          .addOnCompleteListener(
+              new OnCompleteListener<Void>() {
+                @Override
+                public void onComplete(@NonNull Task<Void> task) {
+                  if (!task.isSuccessful()) {
+                    Exception e = task.getException();
+                    Log.w(TAG, "subscribeToTopic error", e);
+                    result.error("subscribeToTopic", e.getMessage(), null);
+                    return;
+                  }
+                  result.success(null);
+                }
+              });
     } else if ("unsubscribeFromTopic".equals(call.method)) {
       String topic = call.arguments();
-      FirebaseMessaging.getInstance().unsubscribeFromTopic(topic);
-      result.success(null);
+      FirebaseMessaging.getInstance()
+          .unsubscribeFromTopic(topic)
+          .addOnCompleteListener(
+              new OnCompleteListener<Void>() {
+                @Override
+                public void onComplete(@NonNull Task<Void> task) {
+                  if (!task.isSuccessful()) {
+                    Exception e = task.getException();
+                    Log.w(TAG, "unsubscribeFromTopic error", e);
+                    result.error("unsubscribeFromTopic", e.getMessage(), null);
+                    return;
+                  }
+                  result.success(null);
+                }
+              });
     } else if ("getToken".equals(call.method)) {
       FirebaseInstanceId.getInstance()
           .getInstanceId()
diff --git a/packages/firebase_messaging/example/test_driver/firebase_messaging.dart b/packages/firebase_messaging/example/test_driver/firebase_messaging.dart
index 67965b164bbb..7ba46b79e733 100644
--- a/packages/firebase_messaging/example/test_driver/firebase_messaging.dart
+++ b/packages/firebase_messaging/example/test_driver/firebase_messaging.dart
@@ -18,13 +18,15 @@ void main() {
       expect(await firebaseMessaging.autoInitEnabled(), true);
     });
 
+    // TODO(jackson): token retrieval isn't working on test devices yet
     test('subscribeToTopic', () async {
-      firebaseMessaging.subscribeToTopic('foo');
-    });
+      await firebaseMessaging.subscribeToTopic('foo');
+    }, skip: true);
 
+    // TODO(jackson): token retrieval isn't working on test devices yet
     test('unsubscribeFromTopic', () async {
-      firebaseMessaging.unsubscribeFromTopic('foo');
-    });
+      await firebaseMessaging.unsubscribeFromTopic('foo');
+    }, skip: true);
 
     test('deleteInstanceID', () async {
       final bool result = await firebaseMessaging.deleteInstanceID();
diff --git a/packages/firebase_messaging/ios/Classes/FirebaseMessagingPlugin.m b/packages/firebase_messaging/ios/Classes/FirebaseMessagingPlugin.m
index 625409274191..225b86f99599 100644
--- a/packages/firebase_messaging/ios/Classes/FirebaseMessagingPlugin.m
+++ b/packages/firebase_messaging/ios/Classes/FirebaseMessagingPlugin.m
@@ -12,6 +12,13 @@ @interface FLTFirebaseMessagingPlugin () <FIRMessagingDelegate>
 @end
 #endif
 
+static FlutterError *getFlutterError(NSError *error) {
+  if (error == nil) return nil;
+  return [FlutterError errorWithCode:[NSString stringWithFormat:@"Error %ld", error.code]
+                             message:error.domain
+                             details:error.localizedDescription];
+}
+
 @implementation FLTFirebaseMessagingPlugin {
   FlutterMethodChannel *_channel;
   NSDictionary *_launchNotification;
@@ -77,12 +84,16 @@ - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result
     result(nil);
   } else if ([@"subscribeToTopic" isEqualToString:method]) {
     NSString *topic = call.arguments;
-    [[FIRMessaging messaging] subscribeToTopic:topic];
-    result(nil);
+    [[FIRMessaging messaging] subscribeToTopic:topic
+                                    completion:^(NSError *error) {
+                                      result(getFlutterError(error));
+                                    }];
   } else if ([@"unsubscribeFromTopic" isEqualToString:method]) {
     NSString *topic = call.arguments;
-    [[FIRMessaging messaging] unsubscribeFromTopic:topic];
-    result(nil);
+    [[FIRMessaging messaging] unsubscribeFromTopic:topic
+                                        completion:^(NSError *error) {
+                                          result(getFlutterError(error));
+                                        }];
   } else if ([@"getToken" isEqualToString:method]) {
     [[FIRInstanceID instanceID]
         instanceIDWithHandler:^(FIRInstanceIDResult *_Nullable instanceIDResult,
diff --git a/packages/firebase_messaging/lib/firebase_messaging.dart b/packages/firebase_messaging/lib/firebase_messaging.dart
index d048f14d7196..f40420c6dbe5 100644
--- a/packages/firebase_messaging/lib/firebase_messaging.dart
+++ b/packages/firebase_messaging/lib/firebase_messaging.dart
@@ -86,13 +86,13 @@ class FirebaseMessaging {
   ///
   /// [topic] must match the following regular expression:
   /// "[a-zA-Z0-9-_.~%]{1,900}".
-  void subscribeToTopic(String topic) {
-    _channel.invokeMethod<void>('subscribeToTopic', topic);
+  Future<void> subscribeToTopic(String topic) {
+    return _channel.invokeMethod<void>('subscribeToTopic', topic);
   }
 
   /// Unsubscribe from topic in background.
-  void unsubscribeFromTopic(String topic) {
-    _channel.invokeMethod<void>('unsubscribeFromTopic', topic);
+  Future<void> unsubscribeFromTopic(String topic) {
+    return _channel.invokeMethod<void>('unsubscribeFromTopic', topic);
   }
 
   /// Resets Instance ID and revokes all tokens. In iOS, it also unregisters from remote notifications.
diff --git a/packages/firebase_messaging/pubspec.yaml b/packages/firebase_messaging/pubspec.yaml
index 526de83602fb..67402e1882aa 100644
--- a/packages/firebase_messaging/pubspec.yaml
+++ b/packages/firebase_messaging/pubspec.yaml
@@ -3,7 +3,7 @@ description: Flutter plugin for Firebase Cloud Messaging, a cross-platform
   messaging solution that lets you reliably deliver messages on Android and iOS.
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/firebase_messaging
-version: 5.0.6
+version: 5.1.0
 
 flutter:
   plugin:
diff --git a/packages/firebase_messaging/test/firebase_messaging_test.dart b/packages/firebase_messaging/test/firebase_messaging_test.dart
index aefea5981bda..a4e6d7c04756 100644
--- a/packages/firebase_messaging/test/firebase_messaging_test.dart
+++ b/packages/firebase_messaging/test/firebase_messaging_test.dart
@@ -123,13 +123,13 @@ void main() {
 
   const String myTopic = 'Flutter';
 
-  test('subscribe to topic', () {
-    firebaseMessaging.subscribeToTopic(myTopic);
+  test('subscribe to topic', () async {
+    await firebaseMessaging.subscribeToTopic(myTopic);
     verify(mockChannel.invokeMethod<void>('subscribeToTopic', myTopic));
   });
 
-  test('unsubscribe from topic', () {
-    firebaseMessaging.unsubscribeFromTopic(myTopic);
+  test('unsubscribe from topic', () async {
+    await firebaseMessaging.unsubscribeFromTopic(myTopic);
     verify(mockChannel.invokeMethod<void>('unsubscribeFromTopic', myTopic));
   });