diff --git a/openevolve/controller.py b/openevolve/controller.py
index 00fd311c6..dc03d22d0 100644
--- a/openevolve/controller.py
+++ b/openevolve/controller.py
@@ -157,6 +157,7 @@ def __init__(
             self.llm_evaluator_ensemble,
             self.evaluator_prompt_sampler,
             database=self.database,
+            suffix=Path(self.initial_program_path).suffix,
         )
         self.evaluation_file = evaluation_file
 
diff --git a/openevolve/evaluator.py b/openevolve/evaluator.py
index 80bcac333..bba5bdfad 100644
--- a/openevolve/evaluator.py
+++ b/openevolve/evaluator.py
@@ -44,9 +44,11 @@ def __init__(
         llm_ensemble: Optional[LLMEnsemble] = None,
         prompt_sampler: Optional[PromptSampler] = None,
         database: Optional[ProgramDatabase] = None,
+        suffix: Optional[str]=".py",
     ):
         self.config = config
         self.evaluation_file = evaluation_file
+        self.program_suffix = suffix
         self.llm_ensemble = llm_ensemble
         self.prompt_sampler = prompt_sampler
         self.database = database
@@ -152,7 +154,7 @@ async def evaluate_program(
         last_exception = None
         for attempt in range(self.config.max_retries + 1):
             # Create a temporary file for the program
-            with tempfile.NamedTemporaryFile(suffix=".py", delete=False) as temp_file:
+            with tempfile.NamedTemporaryFile(suffix=self.program_suffix, delete=False) as temp_file:
                 temp_file.write(program_code.encode("utf-8"))
                 temp_file_path = temp_file.name