diff --git a/lib/omniauth/strategies/oauth2.rb b/lib/omniauth/strategies/oauth2.rb
index e445214..468f2aa 100644
--- a/lib/omniauth/strategies/oauth2.rb
+++ b/lib/omniauth/strategies/oauth2.rb
@@ -94,7 +94,7 @@ def callback_phase # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexi
         end
       rescue ::OAuth2::Error, CallbackError => e
         fail!(:invalid_credentials, e)
-      rescue ::Timeout::Error, ::Errno::ETIMEDOUT => e
+      rescue ::Timeout::Error, ::Errno::ETIMEDOUT, ::OAuth2::TimeoutError, ::OAuth2::ConnectionError => e
         fail!(:timeout, e)
       rescue ::SocketError => e
         fail!(:failed_to_connect, e)
diff --git a/omniauth-oauth2.gemspec b/omniauth-oauth2.gemspec
index a3f7407..8a4cf11 100644
--- a/omniauth-oauth2.gemspec
+++ b/omniauth-oauth2.gemspec
@@ -3,8 +3,8 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require "omniauth-oauth2/version"
 
 Gem::Specification.new do |gem|
-  gem.add_dependency "oauth2",     [">= 1.4", "< 3"]
-  gem.add_dependency "omniauth",   "~> 2.0"
+  gem.add_dependency "oauth2",  [">= 2.0.2", "< 3"]
+  gem.add_dependency "omniauth", "~> 2.0"
 
   gem.add_development_dependency "bundler", "~> 2.0"
 
diff --git a/spec/omniauth/strategies/oauth2_spec.rb b/spec/omniauth/strategies/oauth2_spec.rb
index 68b5d62..ff6176c 100644
--- a/spec/omniauth/strategies/oauth2_spec.rb
+++ b/spec/omniauth/strategies/oauth2_spec.rb
@@ -140,6 +140,33 @@ def app
       expect(instance).to receive(:fail!).with(:csrf_detected, anything)
       instance.callback_phase
     end
+
+    describe 'exception handlings' do
+      let(:params) do
+        {"code" => "code", "state" => state}
+      end
+
+      before do
+        allow_any_instance_of(OmniAuth::Strategies::OAuth2).to receive(:build_access_token).and_raise(exception)
+      end
+
+      {
+        :invalid_credentials => [OAuth2::Error, OmniAuth::Strategies::OAuth2::CallbackError],
+        :timeout => [Timeout::Error, Errno::ETIMEDOUT, OAuth2::TimeoutError, OAuth2::ConnectionError],
+        :failed_to_connect => [SocketError]
+      }.each do |error_type, exceptions|
+        exceptions.each do |klass|
+          context "when #{klass}" do
+            let(:exception) { klass.new 'error' }
+
+            it do
+              expect(instance).to receive(:fail!).with(error_type, exception)
+              instance.callback_phase
+            end
+          end
+        end
+      end
+    end
   end
 end