diff --git a/android/app/build.gradle b/android/app/build.gradle
index 556b53a7..389aaa2e 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -81,7 +81,11 @@ dependencies {
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.0'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
-    implementation 'com.google.firebase:firebase-core:16.0.1'
+    // Cf. https://firebase.google.com/docs/android/setup#add-sdks.
+    implementation 'com.google.firebase:firebase-analytics:17.2.1'
+    implementation 'com.google.firebase:firebase-auth:19.1.0'
+    implementation 'com.google.firebase:firebase-firestore:21.2.1'
+    // Cf. https://pub.dev/packages/firebase_ml_vision
     api 'com.google.firebase:firebase-ml-vision-image-label-model:17.0.2'
 }
 
diff --git a/android/build.gradle b/android/build.gradle
index 264125da..7f77e24e 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -5,8 +5,8 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
-        classpath 'com.google.gms:google-services:4.0.1'
+        classpath 'com.android.tools.build:gradle:3.5.2'
+        classpath 'com.google.gms:google-services:4.3.2'
     }
 }
 
diff --git a/android/gradle/wrapper/gradle-wrapper.properties b/android/gradle/wrapper/gradle-wrapper.properties
index 62fdcaa7..80ae2898 100644
--- a/android/gradle/wrapper/gradle-wrapper.properties
+++ b/android/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip
diff --git a/lib/routes/firebase_login_ex.dart b/lib/routes/firebase_login_ex.dart
index f42820a1..75a06e15 100644
--- a/lib/routes/firebase_login_ex.dart
+++ b/lib/routes/firebase_login_ex.dart
@@ -95,7 +95,7 @@ class _FirebaseLoginExampleState extends State<FirebaseLoginExample> {
       idToken: googleAuth.idToken,
     );
     // Note: user.providerData[0].photoUrl == googleUser.photoUrl.
-    final user = await kFirebaseAuth.signInWithCredential(credential);
+    final user = (await kFirebaseAuth.signInWithCredential(credential)).user;
     kFirebaseAnalytics.logLogin();
     setState(() => this._user = user);
     return user;
@@ -108,7 +108,7 @@ class _FirebaseLoginExampleState extends State<FirebaseLoginExample> {
       return curUser;
     }
     kFirebaseAuth.signOut();
-    final anonyUser = await kFirebaseAuth.signInAnonymously(); // final
+    final anonyUser = (await kFirebaseAuth.signInAnonymously()).user;
     final userInfo = UserUpdateInfo();
     userInfo.displayName = '${anonyUser.uid.substring(0, 5)}_Guest';
     await anonyUser.updateProfile(userInfo);
@@ -160,12 +160,10 @@ class _FirebaseLoginExampleState extends State<FirebaseLoginExample> {
                       ),
               ),
               ListTile(
-                title: Text(
-                    'Last sign in: ${DateTime.fromMillisecondsSinceEpoch(user.metadata.lastSignInTimestamp)}'),
+                title: Text('Last sign in: ${user.metadata.lastSignInTime}'),
               ),
               ListTile(
-                title: Text(
-                    'Creation time: ${DateTime.fromMillisecondsSinceEpoch(user.metadata.creationTimestamp)}'),
+                title: Text('Creation time: ${user.metadata.creationTime}'),
               ),
               ListTile(title: Text('ProviderData: ${user.providerData}')),
             ],
diff --git a/pubspec.yaml b/pubspec.yaml
index 1dcb01af..4530e8ea 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,13 +14,14 @@ dependencies:
   async: '^2.2.0'
   backdrop: '0.1.8'
   cached_network_image: '1.1.2+1'
-  cloud_firestore: '0.12.6'
+  cloud_firestore: '0.12.9+6'
   english_words: '3.1.5'
   firebase_analytics: '3.0.3'
-  firebase_auth: '0.11.1+7'
-  firebase_database: '3.0.3'
-  firebase_ml_vision: '0.9.0+3'
-  firebase_storage: '3.0.2'
+  firebase_auth: '0.14.0+5'
+  firebase_core: '0.4.0+9'
+  firebase_database: '3.0.7'
+  firebase_ml_vision: '0.9.3'
+  firebase_storage: '3.0.6'
   flutter_bloc: '0.18.3'
   flutter_gallery_assets: '0.1.9+2'
   flutter_markdown: '0.2.0'