diff --git a/google_auth_oauthlib/helpers.py b/google_auth_oauthlib/helpers.py
index 7bade82..19c34b6 100644
--- a/google_auth_oauthlib/helpers.py
+++ b/google_auth_oauthlib/helpers.py
@@ -132,6 +132,7 @@ def credentials_from_session(session, client_config=None):
     credentials = google.oauth2.credentials.Credentials(
         session.token['access_token'],
         refresh_token=session.token.get('refresh_token'),
+        id_token=session.token.get('id_token'),
         token_uri=client_config.get('token_uri'),
         client_id=client_config.get('client_id'),
         client_secret=client_config.get('client_secret'),
diff --git a/tests/test_flow.py b/tests/test_flow.py
index 52752c1..3379140 100644
--- a/tests/test_flow.py
+++ b/tests/test_flow.py
@@ -135,6 +135,7 @@ def test_credentials(self, instance):
         instance.oauth2session.token = {
             'access_token': mock.sentinel.access_token,
             'refresh_token': mock.sentinel.refresh_token,
+            'id_token': mock.sentinel.id_token,
             'expires_at': 643969200.0
         }
 
@@ -143,6 +144,7 @@ def test_credentials(self, instance):
         assert credentials.token == mock.sentinel.access_token
         assert credentials.expiry == datetime.datetime(1990, 5, 29, 8, 20, 0)
         assert credentials._refresh_token == mock.sentinel.refresh_token
+        assert credentials.id_token == mock.sentinel.id_token
         assert (credentials._client_id ==
                 CLIENT_SECRETS_INFO['web']['client_id'])
         assert (credentials._client_secret ==
@@ -154,6 +156,7 @@ def test_authorized_session(self, instance):
         instance.oauth2session.token = {
             'access_token': mock.sentinel.access_token,
             'refresh_token': mock.sentinel.refresh_token,
+            'id_token': mock.sentinel.id_token,
             'expires_at': 643969200.0
         }
 
@@ -177,6 +180,7 @@ def set_token(*args, **kwargs):
             instance.oauth2session.token = {
                 'access_token': mock.sentinel.access_token,
                 'refresh_token': mock.sentinel.refresh_token,
+                'id_token': mock.sentinel.id_token,
                 'expires_at': 643969200.0
             }
 
@@ -195,6 +199,7 @@ def test_run_console(self, input_mock, instance, mock_fetch_token):
 
         assert credentials.token == mock.sentinel.access_token
         assert credentials._refresh_token == mock.sentinel.refresh_token
+        assert credentials.id_token == mock.sentinel.id_token
 
         mock_fetch_token.assert_called_with(
             CLIENT_SECRETS_INFO['web']['token_uri'],
@@ -223,6 +228,7 @@ def test_run_local_server(
 
         assert credentials.token == mock.sentinel.access_token
         assert credentials._refresh_token == mock.sentinel.refresh_token
+        assert credentials.id_token == mock.sentinel.id_token
         assert webbrowser_mock.open.called
 
         expected_auth_response = auth_redirect_url.replace('http', 'https')
diff --git a/tests/test_helpers.py b/tests/test_helpers.py
index ce61bd5..ffcec29 100644
--- a/tests/test_helpers.py
+++ b/tests/test_helpers.py
@@ -75,6 +75,7 @@ def test_credentials_from_session(session):
     session.token = {
         'access_token': mock.sentinel.access_token,
         'refresh_token': mock.sentinel.refresh_token,
+        'id_token': mock.sentinel.id_token,
         'expires_at': 643969200.0
     }
 
@@ -84,6 +85,7 @@ def test_credentials_from_session(session):
     assert credentials.token == mock.sentinel.access_token
     assert credentials.expiry == datetime.datetime(1990, 5, 29, 8, 20, 0)
     assert credentials._refresh_token == mock.sentinel.refresh_token
+    assert credentials.id_token == mock.sentinel.id_token
     assert credentials._client_id == CLIENT_SECRETS_INFO['web']['client_id']
     assert (credentials._client_secret ==
             CLIENT_SECRETS_INFO['web']['client_secret'])