diff --git a/optimizely/config_manager.py b/optimizely/config_manager.py
index b1e5b02d..5c0ee342 100644
--- a/optimizely/config_manager.py
+++ b/optimizely/config_manager.py
@@ -1,4 +1,4 @@
-# Copyright 2019, Optimizely
+# Copyright 2019-2020, Optimizely
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -26,6 +26,7 @@
 from .notification_center import NotificationCenter
 from .helpers import enums
 from .helpers import validator
+from .optimizely_config import OptimizelyConfigService
 
 ABC = abc.ABCMeta('ABC', (object,), {'__slots__': ()})
 
@@ -89,6 +90,7 @@ def __init__(
             logger=logger, error_handler=error_handler, notification_center=notification_center,
         )
         self._config = None
+        self.optimizely_config = None
         self.validate_schema = not skip_json_validation
         self._set_config(datafile)
 
@@ -128,6 +130,7 @@ def _set_config(self, datafile):
             return
 
         self._config = config
+        self.optimizely_config = OptimizelyConfigService(config).get_config()
         self.notification_center.send_notifications(enums.NotificationTypes.OPTIMIZELY_CONFIG_UPDATE)
         self.logger.debug(
             'Received new datafile and updated config. '
diff --git a/optimizely/optimizely.py b/optimizely/optimizely.py
index 72496edc..3e8de499 100644
--- a/optimizely/optimizely.py
+++ b/optimizely/optimizely.py
@@ -751,4 +751,8 @@ def get_optimizely_config(self):
             self.logger.error(enums.Errors.INVALID_PROJECT_CONFIG.format('get_optimizely_config'))
             return None
 
+        # Customized Config Manager may not have optimizely_config defined.
+        if hasattr(self.config_manager, 'optimizely_config'):
+            return self.config_manager.optimizely_config
+
         return OptimizelyConfigService(project_config).get_config()
diff --git a/tests/test_config_manager.py b/tests/test_config_manager.py
index c7425f4c..b2117a17 100644
--- a/tests/test_config_manager.py
+++ b/tests/test_config_manager.py
@@ -1,4 +1,4 @@
-# Copyright 2019, Optimizely
+# Copyright 2019-2020, Optimizely
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -18,6 +18,7 @@
 
 from optimizely import config_manager
 from optimizely import exceptions as optimizely_exceptions
+from optimizely import optimizely_config
 from optimizely import project_config
 from optimizely.helpers import enums
 
@@ -75,13 +76,19 @@ def test_set_config__success(self):
         )
         mock_notification_center.send_notifications.assert_called_once_with('OPTIMIZELY_CONFIG_UPDATE')
 
+        self.assertIsInstance(
+            project_config_manager.optimizely_config,
+            optimizely_config.OptimizelyConfig
+        )
+
     def test_set_config__twice(self):
         """ Test calling set_config twice with same content to ensure config is not updated. """
         test_datafile = json.dumps(self.config_dict_with_features)
         mock_logger = mock.Mock()
         mock_notification_center = mock.Mock()
 
-        with mock.patch('optimizely.config_manager.BaseConfigManager._validate_instantiation_options'):
+        with mock.patch('optimizely.config_manager.BaseConfigManager._validate_instantiation_options'), \
+                mock.patch('optimizely.optimizely_config.OptimizelyConfigService.get_config') as mock_opt_service:
             project_config_manager = config_manager.StaticConfigManager(
                 datafile=test_datafile, logger=mock_logger, notification_center=mock_notification_center,
             )
@@ -92,14 +99,18 @@ def test_set_config__twice(self):
         )
         self.assertEqual(1, mock_logger.debug.call_count)
         mock_notification_center.send_notifications.assert_called_once_with('OPTIMIZELY_CONFIG_UPDATE')
+        self.assertEqual(1, mock_opt_service.call_count)
 
         mock_logger.reset_mock()
         mock_notification_center.reset_mock()
+        mock_opt_service.reset_mock()
 
         # Call set config again and confirm that no new log message denoting config update is there
         project_config_manager._set_config(test_datafile)
         self.assertEqual(0, mock_logger.debug.call_count)
         self.assertEqual(0, mock_notification_center.call_count)
+        # Assert that mock_opt_service is not called again.
+        self.assertEqual(0, mock_opt_service.call_count)
 
     def test_set_config__schema_validation(self):
         """ Test set_config calls or does not call schema validation based on skip_json_validation value. """
diff --git a/tests/test_optimizely.py b/tests/test_optimizely.py
index 44bbf27e..4770bcdb 100644
--- a/tests/test_optimizely.py
+++ b/tests/test_optimizely.py
@@ -3945,6 +3945,29 @@ def test_get_optimizely_config_returns_instance_of_optimizely_config(self):
         opt_config = opt_obj.get_optimizely_config()
         self.assertIsInstance(opt_config, optimizely_config.OptimizelyConfig)
 
+    def test_get_optimizely_config_with_custom_config_manager(self):
+        """ Test that get_optimizely_config returns a valid instance of OptimizelyConfig
+        when a custom config manager is used. """
+
+        some_obj = optimizely.Optimizely(json.dumps(self.config_dict_with_features))
+        return_config = some_obj.config_manager.get_config()
+
+        class SomeConfigManager(object):
+            def get_config(self):
+                return return_config
+
+        opt_obj = optimizely.Optimizely(config_manager=SomeConfigManager())
+        self.assertIsInstance(
+            opt_obj.get_optimizely_config(),
+            optimizely_config.OptimizelyConfig
+        )
+
+        with mock.patch('optimizely.optimizely_config.OptimizelyConfigService.get_config') as mock_opt_service:
+            opt_obj = optimizely.Optimizely(config_manager=SomeConfigManager())
+            opt_obj.get_optimizely_config()
+
+        self.assertEqual(1, mock_opt_service.call_count)
+
 
 class OptimizelyWithExceptionTest(base.BaseTest):
     def setUp(self):