diff --git a/openevolve/config.py b/openevolve/config.py
index dbcb9cef..64553b55 100644
--- a/openevolve/config.py
+++ b/openevolve/config.py
@@ -5,7 +5,7 @@
 import os
 from dataclasses import dataclass, field
 from pathlib import Path
-from typing import Any, Dict, List, Optional, Union
+from typing import Any, Callable, Dict, List, Optional, Union
 
 import yaml
 
@@ -19,6 +19,9 @@ class LLMModelConfig:
     api_key: Optional[str] = None
     name: str = None
 
+    # Custom LLM client
+    init_client: Optional[Callable] = None
+
     # Weight for model in ensemble
     weight: float = 1.0
 
diff --git a/openevolve/llm/ensemble.py b/openevolve/llm/ensemble.py
index f5db7be2..749b46aa 100644
--- a/openevolve/llm/ensemble.py
+++ b/openevolve/llm/ensemble.py
@@ -21,7 +21,7 @@ def __init__(self, models_cfg: List[LLMModelConfig]):
         self.models_cfg = models_cfg
 
         # Initialize models from the configuration
-        self.models = [OpenAILLM(model_cfg) for model_cfg in models_cfg]
+        self.models = [model_cfg.init_client(model_cfg) if model_cfg.init_client else OpenAILLM(model_cfg) for model_cfg in models_cfg]
 
         # Extract and normalize model weights
         self.weights = [model.weight for model in models_cfg]
diff --git a/tests/test_llm_ensemble.py b/tests/test_llm_ensemble.py
index 72e9c134..f4a2f3ff 100644
--- a/tests/test_llm_ensemble.py
+++ b/tests/test_llm_ensemble.py
@@ -2,10 +2,11 @@
 Tests for LLMEnsemble in openevolve.llm.ensemble
 """
 
+from typing import Any, Dict, List
 import unittest
 from openevolve.llm.ensemble import LLMEnsemble
 from openevolve.config import LLMModelConfig
-
+from openevolve.llm.base import LLMInterface
 
 class TestLLMEnsemble(unittest.TestCase):
     def test_weighted_sampling(self):
@@ -34,5 +35,32 @@ def test_weighted_sampling(self):
         self.assertEqual(len(sampled_models), len(models))
 
 
+
+class TestEnsembleInit(unittest.TestCase):
+    class MyCustomLLM(LLMInterface):
+        def __init__(self, model, some_field):
+            self.model = model
+            self.some_field = some_field
+
+        async def generate(self, prompt: str, **kwargs) -> str:
+            return "custom-generate"
+
+        async def generate_with_context(self, system_message: str, messages: List[Dict[str, str]], **kwargs) -> str:
+            return "custom-generate-with-context"
+
+    def init_custom_llm(self, model_cfg):
+        return self.MyCustomLLM(model=model_cfg.name, some_field="value")
+
+    def test_ensemble_initialization(self):
+        models = [
+            LLMModelConfig(name="a"),
+            LLMModelConfig(name="b", init_client=self.init_custom_llm),
+        ]
+        ensemble = LLMEnsemble(models)
+        self.assertEqual(len(ensemble.models), len(models))
+        self.assertEqual(ensemble.models[0].model, "a")
+        self.assertEqual(ensemble.models[1].model, "b")
+        self.assertEqual(ensemble.models[1].some_field, "value")
+
 if __name__ == "__main__":
     unittest.main()