diff --git a/tests/proxy_unit_tests/test_proxy_server.py b/tests/proxy_unit_tests/test_proxy_server.py
index 64bb67b58..f0bcc7190 100644
--- a/tests/proxy_unit_tests/test_proxy_server.py
+++ b/tests/proxy_unit_tests/test_proxy_server.py
@@ -2125,3 +2125,73 @@ async def test_proxy_server_prisma_setup_invalid_db():
 
     if _old_db_url:
         os.environ["DATABASE_URL"] = _old_db_url
+
+
+@pytest.mark.asyncio
+async def test_async_log_proxy_authentication_errors():
+    """
+    Test if async_log_proxy_authentication_errors correctly logs authentication errors through custom loggers
+    """
+    import json
+    from fastapi import Request
+    from litellm.proxy.utils import ProxyLogging
+    from litellm.caching import DualCache
+    from litellm.integrations.custom_logger import CustomLogger
+
+    # Create a mock custom logger to verify it's called
+    class MockCustomLogger(CustomLogger):
+        def __init__(self):
+            self.called = False
+            self.exception_logged = None
+            self.request_data_logged = None
+            self.user_api_key_dict_logged = None
+
+        async def async_post_call_failure_hook(
+            self,
+            request_data: dict,
+            original_exception: Exception,
+            user_api_key_dict: UserAPIKeyAuth,
+        ):
+            self.called = True
+            self.exception_logged = original_exception
+            self.request_data_logged = request_data
+            print("logged request_data", request_data)
+            if isinstance(request_data, AsyncMock):
+                self.request_data_logged = (
+                    await request_data()
+                )  # get the actual value from AsyncMock
+            else:
+                self.request_data_logged = request_data
+            self.user_api_key_dict_logged = user_api_key_dict
+
+    # Create test data
+    test_data = {"model": "gpt-4", "messages": [{"role": "user", "content": "Hello"}]}
+
+    # Create a mock request
+    request = Request(scope={"type": "http", "method": "POST"})
+    request._json = AsyncMock(return_value=test_data)
+
+    # Create a test exception
+    test_exception = Exception("Invalid API Key")
+
+    # Initialize ProxyLogging
+    mock_logger = MockCustomLogger()
+    litellm.callbacks = [mock_logger]
+    proxy_logging_obj = ProxyLogging(user_api_key_cache=DualCache())
+
+    # Call the method
+    await proxy_logging_obj.async_log_proxy_authentication_errors(
+        original_exception=test_exception,
+        request=request,
+        parent_otel_span=None,
+        api_key="test-key",
+    )
+
+    # Verify the mock logger was called with correct parameters
+    assert mock_logger.called == True
+    assert mock_logger.exception_logged == test_exception
+    assert mock_logger.request_data_logged == test_data
+    assert mock_logger.user_api_key_dict_logged is not None
+    assert (
+        mock_logger.user_api_key_dict_logged.token is not None
+    )  # token should be hashed