diff --git a/android/app/build.gradle.dev b/android/app/build.gradle.dev
index afe4c0f59..f7ab77d6b 100644
--- a/android/app/build.gradle.dev
+++ b/android/app/build.gradle.dev
@@ -38,7 +38,7 @@ android {
 
     defaultConfig {
         applicationId "com.invoiceninja.app"
-        minSdkVersion 18
+        minSdkVersion 19
         targetSdkVersion 29
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
diff --git a/android/app/build.gradle.prod b/android/app/build.gradle.prod
index ef3b9bbd2..65e4c4292 100644
--- a/android/app/build.gradle.prod
+++ b/android/app/build.gradle.prod
@@ -23,6 +23,7 @@ if (flutterVersionName == null) {
 
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
+apply plugin: 'com.google.gms.google-services'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 def keystorePropertiesFile = rootProject.file("key.properties")
@@ -42,7 +43,7 @@ android {
 
     defaultConfig {
         applicationId "com.invoiceninja.app"
-        minSdkVersion 18
+        minSdkVersion 19
         targetSdkVersion 29
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
diff --git a/lib/utils/oauth.dart b/lib/utils/oauth.dart
index aa41ff1f4..b4ba80f21 100644
--- a/lib/utils/oauth.dart
+++ b/lib/utils/oauth.dart
@@ -24,7 +24,10 @@ class GoogleOAuth {
 
     if (account != null) {
       account.authentication.then((GoogleSignInAuthentication value) {
-        callback(value.idToken, value.accessToken);
+        callback(
+          value.idToken ?? '',
+          value.accessToken ?? '',
+        );
       });
 
       return true;
@@ -38,7 +41,10 @@ class GoogleOAuth {
     final account = await _googleSignIn.signIn();
     if (account != null) {
       account.authentication.then((GoogleSignInAuthentication value) {
-        callback(value.idToken, value.accessToken);
+        callback(
+          value.idToken ?? '',
+          value.accessToken ?? '',
+        );
       });
 
       return true;
diff --git a/pubspec.foss.yaml b/pubspec.foss.yaml
index 131e62c44..b146bdf50 100644
--- a/pubspec.foss.yaml
+++ b/pubspec.foss.yaml
@@ -64,7 +64,6 @@ dependencies:
   # quick_actions: ^0.2.1
   # idb_shim: ^1.11.1+1
 
-  # firebase_auth: 0.15.2 #https://github.com/FirebaseExtended/flutterfire/issues/2433#issuecomment-622438185
   # google_sign_in: ^5.0.7
   # contacts_service: ^0.6.1
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 57191a3ce..72257c3e2 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -64,7 +64,6 @@ dependencies:
   # quick_actions: ^0.2.1
   # idb_shim: ^1.11.1+1
 
-  # firebase_auth: 0.15.2 #https://github.com/FirebaseExtended/flutterfire/issues/2433#issuecomment-622438185
   google_sign_in: ^5.0.7
   contacts_service: ^0.6.1