diff --git a/README.md b/README.md
index 82e9e96..303fbd9 100644
--- a/README.md
+++ b/README.md
@@ -1043,10 +1043,10 @@ tasks = client.get_image_tasks(project="YOUR_PROJECT_SLUG")
 client.export_coco(tasks)
 ```
 
-Export with specifying output directory.
+Export with specifying output directory and file name.
 
 ```python
-client.export_coco(tasks=tasks, output_dir="YOUR_DIRECTROY")
+client.export_coco(tasks=tasks, output_dir="YOUR_DIRECTROY", output_file_name="YOUR_FILE_NAME")
 ```
 
 If you would like to export pose estimation type annotations, please pass annotations.
@@ -1055,7 +1055,7 @@ If you would like to export pose estimation type annotations, please pass annota
 project_slug = "YOUR_PROJECT_SLUG"
 tasks = client.get_image_tasks(project=project_slug)
 annotations = client.get_annotations(project=project_slug)
-client.export_coco(tasks=tasks, annotations=annotations, output_dir="YOUR_DIRECTROY")
+client.export_coco(tasks=tasks, annotations=annotations, output_dir="YOUR_DIRECTROY", output_file_name="YOUR_FILE_NAME")
 ```
 
 ### YOLO
diff --git a/fastlabel/__init__.py b/fastlabel/__init__.py
index 51bcb67..cd942ce 100644
--- a/fastlabel/__init__.py
+++ b/fastlabel/__init__.py
@@ -1082,7 +1082,7 @@ def __get_yolo_format_annotations(self, dataset_folder_path: str) -> dict:
 
     # Task Convert
 
-    def export_coco(self, tasks: list, annotations: list = [], output_dir: str = os.path.join("output", "coco")) -> None:
+    def export_coco(self, tasks: list, annotations: list = [], output_dir: str = os.path.join("output", "coco"), output_file_name: str = "annotations.json") -> None:
         """
         Convert tasks to COCO format and export as a file.
         If you pass annotations, you can export Pose Estimation type annotations.
@@ -1090,10 +1090,14 @@ def export_coco(self, tasks: list, annotations: list = [], output_dir: str = os.
         tasks is a list of tasks. (Required)
         annotations is a list of annotations. (Optional)
         output_dir is output directory(default: output/coco). (Optional)
+        output_file_name is output file name(default: annotations.json). (Optional)
         """
+        if not utils.is_json_ext(output_file_name):
+            raise FastLabelInvalidException(
+                "Output file name must have a json extension", 422)
         coco = converters.to_coco(tasks, annotations)
         os.makedirs(output_dir, exist_ok=True)
-        file_path = os.path.join(output_dir, "annotations.json")
+        file_path = os.path.join(output_dir, output_file_name)
         with open(file_path, 'w') as f:
             json.dump(coco, f, indent=4, ensure_ascii=False)
 
diff --git a/fastlabel/utils.py b/fastlabel/utils.py
index 1af798f..d78ec65 100644
--- a/fastlabel/utils.py
+++ b/fastlabel/utils.py
@@ -19,6 +19,10 @@ def is_video_supported_ext(file_path: str) -> bool:
     return file_path.lower().endswith('.mp4')
 
 
+def is_json_ext(file_name: str) -> bool:
+    return file_name.lower().endswith('.json')
+
+
 def get_basename(file_path: str) -> str:
     """
     e.g.) file.jpg -> file
diff --git a/setup.py b/setup.py
index 0243625..366d786 100644
--- a/setup.py
+++ b/setup.py
@@ -8,7 +8,7 @@
 
 setuptools.setup(
     name="fastlabel",
-    version="0.11.11",
+    version="0.11.12",
     author="eisuke-ueta",
     author_email="eisuke.ueta@fastlabel.ai",
     description="The official Python SDK for FastLabel API, the Data Platform for AI",