diff --git a/packages/firebase_remote_config/CHANGELOG.md b/packages/firebase_remote_config/CHANGELOG.md
index 7d114c78c614..b5e1ea6bc918 100644
--- a/packages/firebase_remote_config/CHANGELOG.md
+++ b/packages/firebase_remote_config/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 0.3.0+4
+
+* Fix `Bad state: Future already completed` error when initially 
+  calling `RemoteConfig.instance` multiple times in parallel.
+
 ## 0.3.0+3
 
 * Replace deprecated `getFlutterEngine` call on Android.
diff --git a/packages/firebase_remote_config/lib/src/remote_config.dart b/packages/firebase_remote_config/lib/src/remote_config.dart
index 161a2b5b1447..9bd461eb6352 100644
--- a/packages/firebase_remote_config/lib/src/remote_config.dart
+++ b/packages/firebase_remote_config/lib/src/remote_config.dart
@@ -25,17 +25,23 @@ class RemoteConfig extends ChangeNotifier {
   RemoteConfigSettings _remoteConfigSettings;
 
   DateTime get lastFetchTime => _lastFetchTime;
+
   LastFetchStatus get lastFetchStatus => _lastFetchStatus;
+
   RemoteConfigSettings get remoteConfigSettings => _remoteConfigSettings;
 
-  static Completer<RemoteConfig> _instanceCompleter = Completer<RemoteConfig>();
+  @visibleForTesting
+  static Completer<RemoteConfig> instanceCompleter = Completer<RemoteConfig>();
 
   /// Gets the instance of RemoteConfig for the default Firebase app.
   static Future<RemoteConfig> get instance async {
-    if (!_instanceCompleter.isCompleted) {
-      _instanceCompleter.complete(await _getRemoteConfigInstance());
+    if (!instanceCompleter.isCompleted) {
+      final _remoteConfigInstance = await _getRemoteConfigInstance();
+      if (!instanceCompleter.isCompleted) {
+        instanceCompleter.complete(_remoteConfigInstance);
+      }
     }
-    return _instanceCompleter.future;
+    return instanceCompleter.future;
   }
 
   static Future<RemoteConfig> _getRemoteConfigInstance() async {
diff --git a/packages/firebase_remote_config/test/firebase_remote_config_test.dart b/packages/firebase_remote_config/test/firebase_remote_config_test.dart
index 937ac98a5d8d..f5965761191b 100644
--- a/packages/firebase_remote_config/test/firebase_remote_config_test.dart
+++ b/packages/firebase_remote_config/test/firebase_remote_config_test.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+
 import 'package:firebase_remote_config/firebase_remote_config.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -40,6 +42,12 @@ void main() {
       });
     });
 
+    tearDown(() {
+      RemoteConfig.instanceCompleter = Completer<RemoteConfig>();
+      // empty log for next tests
+      log.removeWhere((_) => true);
+    });
+
     test('instance', () async {
       final RemoteConfig remoteConfig = await RemoteConfig.instance;
       expect(
@@ -59,10 +67,12 @@ void main() {
         RemoteConfig.instance,
         RemoteConfig.instance,
       ];
-      Future.wait(futures).then((List<RemoteConfig> remoteConfigs) {
-        // Check that both returned Remote Config instances are the same.
-        expect(remoteConfigs[0], remoteConfigs[1]);
-      });
+      final List<RemoteConfig> remoteConfigs = await Future.wait(futures);
+      // Check that both returned Remote Config instances are the same.
+      expect(remoteConfigs[0], remoteConfigs[1]);
+      // Check that method RemoteConfig#instance was called at least once
+      expect(log.length, isPositive);
+      expect(log[0], isMethodCall('RemoteConfig#instance', arguments: null));
     });
   });