diff --git a/workflows/workflow_use/builder/service.py b/workflows/workflow_use/builder/service.py
index f6d12437..d12e289c 100644
--- a/workflows/workflow_use/builder/service.py
+++ b/workflows/workflow_use/builder/service.py
@@ -327,7 +327,7 @@ async def build_workflow_from_path(
         self, path: Path, user_goal: str
     ) -> WorkflowDefinitionSchema:
         """Build a workflow from a JSON file path."""
-        with open(path, "r") as f:
+        with open(path, "r", encoding="utf-8") as f:
             workflow_data = json.load(f)
 
         workflow_data_schema = WorkflowDefinitionSchema.model_validate(workflow_data)
@@ -337,5 +337,5 @@ async def save_workflow_to_path(
         self, workflow: WorkflowDefinitionSchema, path: Path
     ):
         """Save a workflow to a JSON file path."""
-        with open(path, "w") as f:
+        with open(path, "w", encoding="utf-8") as f:
             json.dump(workflow.model_dump(mode="json"), f, indent=2)