diff --git a/lib/omniauth/strategies/google_oauth2.rb b/lib/omniauth/strategies/google_oauth2.rb
index 1f59ca9..c98c488 100644
--- a/lib/omniauth/strategies/google_oauth2.rb
+++ b/lib/omniauth/strategies/google_oauth2.rb
@@ -69,9 +69,9 @@ def authorize_params
 
       extra do
         hash = {}
-        hash[:id_token] = access_token['id_token']
-        if !options[:skip_jwt] && !access_token['id_token'].nil?
-          decoded = ::JWT.decode(access_token['id_token'], nil, false).first
+        hash[:id_token] = access_token.token
+        if !options[:skip_jwt] && !nil_or_empty(access_token.token)
+          decoded = ::JWT.decode(access_token.token, nil, false).first
 
           # We have to manually verify the claims because the third parameter to
           # JWT.decode is false since no verification key is provided.
@@ -108,6 +108,10 @@ def custom_build_access_token
 
       private
 
+      def nil_or_empty(obj)
+        obj.is_a?(String) ? obj.empty? : obj.nil?
+      end
+
       def callback_url
         options[:redirect_uri] || (full_host + callback_path)
       end
diff --git a/omniauth-google-oauth2.gemspec b/omniauth-google-oauth2.gemspec
index 56c6d87..5c40982 100644
--- a/omniauth-google-oauth2.gemspec
+++ b/omniauth-google-oauth2.gemspec
@@ -21,9 +21,9 @@ Gem::Specification.new do |gem|
   gem.required_ruby_version = '>= 2.2'
 
   gem.add_runtime_dependency 'jwt', '>= 2.0'
-  gem.add_runtime_dependency 'oauth2', '~> 1.1'
+  gem.add_runtime_dependency 'oauth2', '~> 2.0.6'
   gem.add_runtime_dependency 'omniauth', '~> 2.0'
-  gem.add_runtime_dependency 'omniauth-oauth2', '~> 1.7.1'
+  gem.add_runtime_dependency 'omniauth-oauth2', '~> 1.8.0'
 
   gem.add_development_dependency 'rake', '~> 12.0'
   gem.add_development_dependency 'rspec', '~> 3.6'
diff --git a/spec/omniauth/strategies/google_oauth2_spec.rb b/spec/omniauth/strategies/google_oauth2_spec.rb
index 41b0599..4bf1874 100644
--- a/spec/omniauth/strategies/google_oauth2_spec.rb
+++ b/spec/omniauth/strategies/google_oauth2_spec.rb
@@ -339,7 +339,7 @@
         end
       end
     end
-    let(:access_token) { OAuth2::AccessToken.from_hash(client, {}) }
+    let(:access_token) { OAuth2::AccessToken.from_hash(client, { 'access_token' => 'a' }) }
     before { allow(subject).to receive(:access_token).and_return(access_token) }
 
     context 'with verified email' do
@@ -405,8 +405,6 @@
         end
       end
     end
-    let(:access_token) { OAuth2::AccessToken.from_hash(client, {}) }
-
     before { allow(subject).to receive(:access_token).and_return(access_token) }
 
     describe 'id_token' do
@@ -467,7 +465,10 @@
         end
       end
 
-      context 'when the id_token is missing' do
+      context 'when the access token is empty or nil' do
+        let(:access_token) { OAuth2::AccessToken.new(client, nil, { 'refresh_token' => 'foo' }) }
+        before { allow(subject.extra).to receive(:access_token).and_return(access_token) }
+
         it 'should not include id_token' do
           expect(subject.extra).not_to have_key(:id_token)
         end
@@ -479,6 +480,19 @@
     end
 
     describe 'raw_info' do
+      let(:token_info) do
+        {
+          'abc' => 'xyz',
+          'exp' => Time.now.to_i + 3600,
+          'nbf' => Time.now.to_i - 60,
+          'iat' => Time.now.to_i,
+          'aud' => 'appid',
+          'iss' => 'accounts.google.com'
+        }
+      end
+      let(:id_token) { JWT.encode(token_info, 'secret') }
+      let(:access_token) { OAuth2::AccessToken.from_hash(client, 'id_token' => id_token) }
+
       context 'when skip_info is true' do
         before { subject.options[:skip_info] = true }
 
@@ -663,15 +677,22 @@
     end
 
     it 'should read access_token from hash if this is not an AJAX request with a code parameter' do
+      client = OAuth2::Client.new('abc', 'def') do |builder|
+        builder.request :url_encoded
+        builder.adapter :test do |stub|
+          stub.get('/oauth2/v3/userinfo') { [200, { 'content-type' => 'application/json' }, '{"sub": "12345"}'] }
+        end
+      end
+
       allow(request).to receive(:xhr?).and_return(false)
       allow(request).to receive(:params).and_return('access_token' => 'valid_access_token')
       expect(subject).to receive(:verify_token).with('valid_access_token').and_return true
-      expect(subject).to receive(:client).and_return(:client)
+      expect(subject).to receive(:client).and_return(client)
 
       token = subject.build_access_token
       expect(token).to be_instance_of(::OAuth2::AccessToken)
       expect(token.token).to eq('valid_access_token')
-      expect(token.client).to eq(:client)
+      expect(token.client).to eq(client)
     end
 
     it 'reads the code from a json request body' do
@@ -708,18 +729,24 @@
 
     it 'reads the access token from a json request body' do
       body = StringIO.new(%({"access_token":"valid_access_token"}))
+      client = OAuth2::Client.new('abc', 'def') do |builder|
+        builder.request :url_encoded
+        builder.adapter :test do |stub|
+          stub.get('/oauth2/v3/userinfo') { [200, { 'content-type' => 'application/json' }, '{"sub": "12345"}'] }
+        end
+      end
 
       allow(request).to receive(:xhr?).and_return(false)
       allow(request).to receive(:content_type).and_return('application/json')
       allow(request).to receive(:body).and_return(body)
-      expect(subject).to receive(:client).and_return(:client)
+      expect(subject).to receive(:client).and_return(client)
 
       expect(subject).to receive(:verify_token).with('valid_access_token').and_return true
 
       token = subject.build_access_token
       expect(token).to be_instance_of(::OAuth2::AccessToken)
       expect(token.token).to eq('valid_access_token')
-      expect(token.client).to eq(:client)
+      expect(token.client).to eq(client)
     end
 
     it 'should use callback_url without query_string if this is not an AJAX request' do
@@ -795,7 +822,7 @@
         end
       end
     end
-    let(:access_token) { OAuth2::AccessToken.from_hash(client, {}) }
+    let(:access_token) { OAuth2::AccessToken.from_hash(client, { 'access_token' => 'foo' }) }
 
     context 'when domain is nil' do
       let(:client) do