diff --git a/okta/config/config_setter.py b/okta/config/config_setter.py
index 55dd345b8..63026cde4 100644
--- a/okta/config/config_setter.py
+++ b/okta/config/config_setter.py
@@ -12,7 +12,7 @@
 import os
 
 import yaml
-from flatdict import FlatDict
+from flatdict2 import FlatDict
 
 from okta.constants import _GLOBAL_YAML_PATH, _LOCAL_YAML_PATH
 
diff --git a/okta/request_executor.py b/okta/request_executor.py
index 3cc4ecf9f..693359c37 100644
--- a/okta/request_executor.py
+++ b/okta/request_executor.py
@@ -40,7 +40,7 @@ def __init__(self, config, cache, http_client=None):
                              of the Request Executor
         """
         # Raise Value Error if numerical inputs are invalid (< 0)
-        self._request_timeout = config["client"].get("requestTimeout", 0)
+        self._request_timeout = int(config["client"].get("requestTimeout", 0))
         if self._request_timeout < 0:
             raise ValueError(
                 (
@@ -49,7 +49,7 @@ def __init__(self, config, cache, http_client=None):
                     "greater than zero"
                 )
             )
-        self._max_retries = config["client"]["rateLimit"].get("maxRetries", 2)
+        self._max_retries = int(config["client"]["rateLimit"].get("maxRetries", 2))
         if self._max_retries < 0:
             raise ValueError(
                 (
diff --git a/requirements.txt b/requirements.txt
index 9906b789b..cc716b32e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 aenum==3.1.11
 aiohttp==3.12.14
 blinker==1.9.0
-flatdict==4.0.1
+flatdict2==4.0.4
 jwcrypto==1.5.6
 pycryptodomex==3.23.0
 pydantic==2.11.3
diff --git a/setup.py b/setup.py
index 83f102327..4cfdc3d12 100644
--- a/setup.py
+++ b/setup.py
@@ -36,7 +36,7 @@
     "aenum >= 3.1.11",
     "aiohttp >= 3.12.14",
     "blinker >= 1.9.0",
-    "flatdict >= 4.0.1",
+    "flatdict2 >= 4.0.4",
     'jwcrypto >= 1.5.6',
     "pycryptodomex >= 3.23.0",
     "pydantic >= 2.11.3",
diff --git a/tests/unit/test_request_executor.py b/tests/unit/test_request_executor.py
new file mode 100644
index 000000000..2c547aa43
--- /dev/null
+++ b/tests/unit/test_request_executor.py
@@ -0,0 +1,204 @@
+import aiohttp
+import datetime
+import pytest
+import time
+
+from http import HTTPStatus
+from multidict import MultiDict
+from okta.client import Client as OktaClient
+from okta.request_executor import RequestExecutor
+
+
+@pytest.mark.asyncio
+async def test_retry_count_header(monkeypatch):
+    org_url = "https://test.okta.com"
+    token = "TOKEN"
+    config = {'orgUrl': org_url, 'token': token, 'rateLimit': {'maxRetries': 2}}
+    client = OktaClient(config)
+
+    class MockHTTPRequest():
+        """
+        async with aiohttp.request(**params) as response:
+            return (response.request_info,
+                    response,
+                    await response.text(),
+                    None)
+
+        _, res_details, resp_body, error = \
+        headers = res_details.headers
+        """
+
+        def __call__(self, **params):
+            self.request_info = params
+            self.headers = MultiDict(
+                {'Date': datetime.datetime.now(tz=datetime.timezone.utc).strftime('%a, %d %b %Y %H:%M:%S %Z'),
+                 'Content-Type': 'application/json',
+                 'X-Rate-Limit-Limit': 600,
+                 'X-Rate-Limit-Remaining': 599,
+                 'X-Rate-Limit-Reset': str(time.time())}
+            )
+            self.url = params['url']
+            self.content_type = 'application/json'
+            self.links = ''
+            self.text = MockHTTPRequest.mock_response_text
+            self.status = HTTPStatus.TOO_MANY_REQUESTS
+            return self
+
+        async def __aenter__(self):
+            return self
+
+        async def __aexit__(self, exc_type, exc, tb):
+            pass
+
+        @staticmethod
+        async def mock_response_text():
+            return '[{"embedded": null,' \
+                   '"links": {"self": {"href": "https://test.okta.com/v1/users/test_id"}},' \
+                   '"activated": "2021-01-01T00:00:00.000Z",' \
+                   '"created": "2021-01-01T00:00:00.000Z",' \
+                   '"credentials": null,' \
+                   '"id": "test_id",' \
+                   '"last_login": null,' \
+                   '"profile": {"name": "test_name"},' \
+                   '"status": null,' \
+                   '"status_changed": null,' \
+                   '"transitioning_to_status": null,' \
+                   '"type": null}]'
+
+    mock_http_request = MockHTTPRequest()
+    monkeypatch.setattr(aiohttp.ClientSession, 'request', mock_http_request)
+    res, resp_body, error = await client.list_users()
+    # Check request was retried max times and header 'X-Okta-Retry-Count' was set properly
+    assert mock_http_request.request_info['headers'].get('X-Okta-Retry-Count') == '2'
+
+
+def test_is_retryable_status():
+    org_url = "https://test.okta.com"
+    token = "TOKEN"
+    config = {'client': {'orgUrl': org_url,
+                         'token': token,
+                         'rateLimit': {},
+                         'authorizationMode': None}}
+    req_exec = RequestExecutor(config=config, cache=None)
+    assert req_exec.is_retryable_status(HTTPStatus.TOO_MANY_REQUESTS)
+    assert req_exec.is_retryable_status(HTTPStatus.SERVICE_UNAVAILABLE)
+    assert req_exec.is_retryable_status(HTTPStatus.GATEWAY_TIMEOUT)
+    assert not req_exec.is_retryable_status(HTTPStatus.FORBIDDEN)
+
+
+def test_clear_empty_params():
+    org_url = "https://test.okta.com"
+    token = "TOKEN"
+    config = {'client': {'orgUrl': org_url,
+                         'token': token,
+                         'rateLimit': {},
+                         'authorizationMode': None}}
+    req_exec = RequestExecutor(config=config, cache=None)
+
+    body = {'int_value': 0,
+            'str_value': '0',
+            'empty_str_value': '',
+            'list_value': [1, 2, 3],
+            'empty_list_value': [],
+            'dict_value': {'int_value': 0},
+            'empty_dict_value': {},
+            'nested_empty_dict_value': {'list_value': [1, 2, 3], 'empty_list_value': []},
+            'nested_empty_list_value': {'empty_list_value': []}}
+
+    cleared_body = {'int_value': 0,
+                    'str_value': '0',
+                    'list_value': [1, 2, 3],
+                    'dict_value': {'int_value': 0},
+                    'nested_empty_dict_value': {'list_value': [1, 2, 3]}}
+
+    assert req_exec.clear_empty_params(body) == cleared_body
+
+
+class TestRequestExecutorStringConfig:
+    """Tests that string config values (as from env vars) are handled correctly."""
+
+    def _build_config(self, request_timeout=0, max_retries=2):
+        return {'client': {'orgUrl': 'https://test.okta.com',
+                           'token': 'TOKEN',
+                           'rateLimit': {'maxRetries': max_retries},
+                           'requestTimeout': request_timeout,
+                           'authorizationMode': None}}
+
+    def test_request_timeout_string_value(self):
+        """String requestTimeout (e.g. from env var) must be converted to int."""
+        config = self._build_config(request_timeout='30')
+        req_exec = RequestExecutor(config=config, cache=None)
+        assert req_exec._request_timeout == 30
+        assert isinstance(req_exec._request_timeout, int)
+
+    def test_max_retries_string_value(self):
+        """String maxRetries (e.g. from env var) must be converted to int."""
+        config = self._build_config(max_retries='4')
+        req_exec = RequestExecutor(config=config, cache=None)
+        assert req_exec._max_retries == 4
+        assert isinstance(req_exec._max_retries, int)
+
+    def test_request_timeout_int_value(self):
+        """Int requestTimeout should still work as before."""
+        config = self._build_config(request_timeout=30)
+        req_exec = RequestExecutor(config=config, cache=None)
+        assert req_exec._request_timeout == 30
+
+    def test_max_retries_int_value(self):
+        """Int maxRetries should still work as before."""
+        config = self._build_config(max_retries=4)
+        req_exec = RequestExecutor(config=config, cache=None)
+        assert req_exec._max_retries == 4
+
+    def test_request_timeout_zero_string(self):
+        """String '0' for requestTimeout (disabled) must work."""
+        config = self._build_config(request_timeout='0')
+        req_exec = RequestExecutor(config=config, cache=None)
+        assert req_exec._request_timeout == 0
+
+    def test_max_retries_zero_string(self):
+        """String '0' for maxRetries (disabled) must work."""
+        config = self._build_config(max_retries='0')
+        req_exec = RequestExecutor(config=config, cache=None)
+        assert req_exec._max_retries == 0
+
+    def test_request_timeout_negative_string_raises(self):
+        """Negative string requestTimeout must still raise ValueError."""
+        config = self._build_config(request_timeout='-1')
+        with pytest.raises(ValueError):
+            RequestExecutor(config=config, cache=None)
+
+    def test_max_retries_negative_string_raises(self):
+        """Negative string maxRetries must still raise ValueError."""
+        config = self._build_config(max_retries='-1')
+        with pytest.raises(ValueError):
+            RequestExecutor(config=config, cache=None)
+
+
+@pytest.mark.parametrize(
+    "accept_header",
+    ["", "application/xml", "application/json",
+        "text/html", "application/xhtml+xml", "image/jpeg"]
+)
+@pytest.mark.asyncio
+async def test_overwrite_default_request_executor_headers(accept_header):
+    org_url = "https://test.okta.com"
+    token = "TOKEN"
+    config = {'client': {'orgUrl': org_url,
+                         'token': token,
+                         'rateLimit': {},
+                         'authorizationMode': None}}
+    req_exec = RequestExecutor(config=config, cache=None)
+
+    # overwrite headers if parameter present
+    header_overwrite = {'Accept': accept_header} if accept_header else {}
+    request, error = await req_exec.create_request(
+        'GET',
+        f'{org_url}/api/v1/users',
+        {},
+        header_overwrite,
+        {}
+    )
+    assert request is not None
+    assert request["headers"]["Accept"] ==\
+        accept_header if accept_header else "application/json"